
285 S.W.3d 884 (2009)
Clark Dewayne MAYS, Appellant,
v.
The STATE of Texas.
No. PD-0670-07.
Court of Criminal Appeals of Texas.
April 22, 2009.
Rehearing Denied June 24, 2009.
*886 Lydia M.V. Brandt, Richardson, for Appellant.
Lisa C. McMinn, Asst. State's Atty., Jeffrey L. Van Horn, State's Atty., Austin, for State.
WOMACK, J., delivered the opinion of the Court, in which KELLER, P.J., and PRICE, KEASLER, HERVEY, and COCHRAN, JJ., joined.
The appellant, during voir dire in a murder trial, sought to raise the subject of diminished capacity as it affects a defendant's culpable mental state at the time of the offense. The trial court ruled that it would exclude any evidence of the appellant's diminished capacity and invited the appellant to proffer evidence. The State here raises the issue of whether the appellant's proffer of evidence was sufficient to preserve that ruling for appeal. Holding that it was not sufficient, we shall reverse the judgment of the Court of Appeals.

Trial Proceedings
The appellant was charged with capital murder;[1] the State chose not to seek the death penalty. The case proceeded to trial before a jury. During voir dire, the appellant made the following statement: "The law in Texas is that we can look at [defendants'] history, their medical history, their psychological history, their psychiatric history, and we can look at those factors to determine their state of mind." The prosecution responded, "Your Honor, may we approach?" The judge excused the jury from the courtroom. There followed a discussion wherein the trial judge considered the admissibility of mental-impairment evidence.
At the outset of the discussion, the trial court ruled:
After reading the Jackson case, it appears to me that there is no defense of diminished capacity. There is no need for this type of evidence of diminished capacity for the purposes of sentencing because there is no issue of sentencing, there is only an issue of guilt or innocence, so I've ruled that I will not hear any evidence of diminished capacity. [Defense Counsel] asked for an opportunity to make a record and I'm glad to give him that opportunity. You may proceed.
Defense counsel proceeded to argue that, although Jackson v. State[2] rejected diminished capacity as an affirmative defense in Texas, it recognized the relevance and admissibility of evidence of mental impairment to "show that the defendant lacked the capacity, if you will, to form the specific intent or the intent element of murder." He then stated: "[T]he evidence in this case, were we allowed to present it, would show that because of mental and medical impairment, the defendant lacked, at the time of the alleged commission of this crime, the ability to form the requisites of the mental state required of intentional and knowing." He also outlined the applicable Texas law that he believed rendered the evidence admissible.
Defense counsel reviewed with the court each of a series of slides he had prepared to show and discuss with the jury panel during voir dire. For instance, Defendant's Exhibit 1 (mistakenly marked in the record as State's Exhibit 1) said:
CONDITION OF THE MIND: You are instructed that you may consider all relevant facts and circumstances surrounding the killing, if any, and the previous relationship existing between the accused *887 and the deceased, if any, together with all relevant facts and circumstances going to show the condition of the mind of the accused at the time of the offense, if any.
Defense counsel summarized his planned discussion with the jury panel, with regard to this slide, as follows:
[W]e would have voir dired the jury as it relates to the condition of the mind of the accused at the time of the offense. We would have asked questions concerning Article 38.36 as it relates to relevant facts and circumstances going to show the condition of the mind.[3]
The subjects of the remaining slides and counsel's summary of them were similarly confined to Texas law regarding mental states and lesser-included offenses, as well as general statements regarding the questions counsel anticipated asking the panel. Counsel offered the slides as exhibits, and the court admitted them for the record.
Defense counsel further objected to the ruling against using the evidence for voir dire. The trial judge affirmed his ruling and reiterated his understanding that Jackson allowed diminished-capacity evidence only at punishment, not at the guilt phase. Because punishment was not at issue in this case, he said that the evidence would not be admissible. He also excluded the evidence because of prejudice, irrelevance, and confusion to the jury. Defense counsel argued these points and finally stated:
Judge, my position is that the blanket exclusion of evidence of mental impairment in the guilt/innocence phase of this trial to show that as a matter of evidence the defendant lacked the ability or capacity, if you will, to form either an intentional or knowing states [sic] of mind as culpable mental states for the offense of murder is not the correct statement of the law.
At this point in time, if we can take that issue up on appeal, without having considered waiving the appeal on the point, we would be of the opinion that if you consented to that, we would enter a plea of guilty to the offense of capital murder in this case. I'm saying that with the reservation that because I have been told that no evidence whatsoever under any circumstances would be admissible as it applies to that issue, that I might not and would not put on any record as to the defendant's past mental health history other than I would offer into evidencewell, I justat this point that's my position.
Now, if we are not willing to go on the record from the court's perspective and say that it just depends on what evidence I heard from whatever mental health expert that you presented, I need to go ahead and bring my mental health expert down and make my record. But if the court's of the opinion, as I understand it as a blanket ruling, that no matter what that evidence said, then I think we have to get into the probative prejudicial point of it because I don't want to waive an appellate point in regards to that aspect of it. But if the court's position is that regardless of the prejudicial element of it, that Texas law does not allow the introduction of evidence of mental impairment in the guilt-innocence phase to show the defendant *888 lacked the capacity to form the necessary mens rea of intentionally or knowingly, I'm willing to proceed forward with the court's permission to appeal that particular point.
The trial judge agreed to certify the appeal[4] and accept the appellant's guilty plea.
The State asked to make an offer of proof from its expert witness, to counter the defendant's expert.
[PROSECUTOR]: I thought that [Defense Counsel] said that he was going to do an offer of proof with an expert.
[DEFENSE COUNSEL]: No, he indicated that he would notas I heard you, judge, not fall back on the probative prejudice argument, and it was a blanket ruling that such evidence was inadmissible. That's how I understood you to say it.
[TRIAL COURT]: That's the way I meant it.
[PROSECUTOR]: In that case, we don't need to do that.
[TRIAL COURT]: It's not necessary to put on any evidence of mental capacity. It's all presumed in the defendant's favor in an appeal of this type.
The appellant pleaded guilty, and his sentence was set automatically at life imprisonment.[5] He appealed.

Court of Appeals Decision
The issue on direct appeal centered on whether the evidence would have been admissible at the guilt phase of the trial and, therefore, whether the trial court erred in excluding it.[6] As the trial court had done, the Court of Appeals analyzed the question under Jackson. The Court said that, although Jackson made plain that Texas jurisprudence does not include an affirmative defense of diminished capacity, it "does, however, recognize something very closely akin to it, ... this being `simply a failure-of-proof defense in which the defendant claims that the State failed to prove that the defendant had the required state of mind at the time of the offense.'"[7]
The Court of Appeals found the appellant's proffer to have fallen within the ambit of the Jackson diminished-capacity doctrine.[8] The Court recognized that "there was no showing of the nature of the evidence which was to be produced."[9] But it looked to the appellant's stated goal for offering the evidence, which "was to show that he would have explored relevant facts and circumstances going to show the condition of his mind at the time of the killing and to apply it to the lesser included *889 offense of negligent homicide."[10] The Court determined this to be a permissible purposeand therefore the evidence to be admissible at the guilt phase of the trial under Jackson, and it concluded that the trial court had abused its discretion in excluding the evidence.[11]
The Court ascribed to the trial court's ruling not only the fact that "no evidence was presented from which [it could] determine whether the trial court's erroneous ruling substantially affected Mays'[s] substantial rights," but also the appellant's guilty plea itself.[12] Because it determined the erroneous ruling to have necessarily contributed to the conviction, the Court reversed the judgment and remanded the case to the trial court.[13] The State petitioned for review.

Our Review
In this court, the State's first ground is whether the appellant failed to preserve error for review. Before we reach the State's ground on its merits, we address the appellant's contention that the preservation issue is not properly before this court.
The appellant argues that the State raises the issue here only for the first time and that the Court of Appeals did not render a decision, either explicit or implicit, on procedural default. Because this court's jurisdiction is limited to reviewing "decisions" of the courts of appeals, he says, we have no jurisdiction to review the issue in this case. We disagree.
This court has said, "Preservation of error is a systemic requirement that a first-level appellate court should ordinarily review on its own motion."[14] Precisely for this reason, in Haley we found a procedural-default question, raised by the State for the first time in its petition for discretionary review, to be properly before this court, and in so deciding, reached the merits of the issue.[15] Moreover, here there is no reason to believe that the Court of Appeals deviated from ordinary procedure. Although neither party raised the issue in the Court of Appeals, it was incumbent upon the Court itself to take up error preservation as a threshold issue. Implicit in the Court's review on the merits was a decision on procedural default, which is therefore properly before this court. Accordingly, we now turn to the question of whether the appellant preserved error.
In order to preserve error regarding a trial court's decision to exclude evidence, the complaining party must comply with Rule of Evidence 103 by making an "offer of proof" which sets forth the substance of the proffered evidence.[16] Rule 103(a)(2) provides: "Error may not be predicated upon a ruling which ... excludes evidence unless a substantial right of the party is affected, and ... the substance of the evidence was made known to the court by offer, or was apparent from the context within which questions were asked." The offer of proof may consist of a concise statement by counsel, or it may be in question-and-answer form.[17] If in *890 the form of a statement, the proffer "must include a reasonably specific summary of the evidence offered and must state the relevance of the evidence unless the relevance is apparent, so that the court can determine whether the evidence is relevant and admissible."[18]
"The primary purpose of an offer of proof is to enable an appellate court to determine whether the exclusion was erroneous and harmful. A secondary purpose is to permit the trial judge to reconsider his ruling in light of the actual evidence."[19]
This court's opinion in Warner is instructive, as it was predicated on a similar set of circumstances. Warner, in a hearing before voir dire on the State's motion in limine, objected to a portion of the motion requesting that the defendant not discuss in front of the jury any evidence concerning his counseling or rehabilitation for a stress disorder.[20] The defendant told the trial court he intended to adduce evidence at the guilt phase that he was a Vietnam War veteran who suffered from post-traumatic stress disorder (PTSD), and that he had received counseling for the disorder.[21] He further contended that the evidence was admissible to prove that he lacked the specific intent to commit the charged offenses.[22] Warner "did not, however, define `post-traumatic stress disorder' for the court or explain how he intended to prove that he suffered from the disorder. [He] also did not explain how evidence of PTSD would be relevant to the question of specific intent."[23] The trial court granted the State's motion and found the evidence to be admissible only at the punishment phase of the trial.[24] Warner did not offer the evidence of PTSD at the guilt phase and was found guilty by a jury.[25]
On direct appeal, Warner argued that the trial court erred in excluding the evidence from the guilt phase. The Third Court of Appeals affirmed. This court initially granted Warner's petition for discretionary review on the same question, but after determining from the record that he had not preserved the error for review, we dismissed his petition as improvidently granted. We concluded that he had not made an adequate offer of proof, either during the hearing on the motion or at the guilt phase.[26]
There can be no doubt that the trial judge in the instant case intended his ruling excluding all evidence of the appellant's diminished capacity to apply, not simply for purposes of voir dire, but to the entire guilt phase of the trial. In order to preserve error, the appellant therefore was obliged to make an offer of proof that extended beyond the anticipated questions to, and topics of discussion with, potential jurors during voir dire. He was required to proffer, with some degree of specificity, the substantive evidence he intended to present, during the guilt phase, of the appellant's mental impairments and their impact on his mental state at the time of the offense. This he failed to do.
*891 The appellant's proffer of his slides and the questions he would have posed to the jury in voir dire provide us with just thatthe substance of his anticipated dialogue with the jury panel. The record reveals that the appellant proffered nothing that rises to the level contemplated in our Rules of Evidence and this court's precedent. The only statement on the record that might even be considered to approach an adequate offer of proof was his statement that, "[T]he evidence in this case, were we allowed to present it, would show that because of mental and medical impairment, the defendant lacked, at the time of the alleged commission of this crime, the ability to form the requisites of the mental state required of intentional and knowing." But as is evident from Warner, this sort of summary, in the most general and cursory terms, without any of the meat of the actual evidence, will not suffice to preserve error. The appellant's counsel himself admitted, during the course of the discussion, "I would say that how could we know if that evidence would be more prejudicial than probative when we haven't even had a chance to see what that evidence is."
This is not a case in which the trial judge afforded the appellant no opportunity to make a proffer. On the contrary, the appellant's counsel had every occasion to make a proper offer of proof. We can see from the excerpts of the record above, however, that both the trial judge and the appellant's counsel were mistaken as to the need for the substance of the proffer which the law requires. The record reflects that trial counsel was prepared to "bring [his] mental health expert down and make [his] record" of the appellant's "past mental health history" had the ruling been more limited in scope. But the appellant's counsel clearly believed that the trial judge's "blanket ruling" excluding evidence of mental impairment from the guilt phase shielded him from the necessity of proffering evidence of the appellant's mental impairment. This is simply incorrect. That the trial judge sanctioned this mistaken belief by agreeing that such a proffer was unnecessary, does not relieve the appellant from his burden. It was the responsibility of the appellant to ensure that the substance of the evidence was placed into the record, and he failed to do so.
Because the appellant failed to make a proper offer of proof, we hold that he did not preserve his complaint for appeal. We reverse the judgment of the Court of Appeals and affirm the judgment of the trial court.[27]
HOLCOMB, J., filed a dissenting opinion, in which MEYERS and JOHNSON, JJ., joined.
HOLCOMB, J., dissenting, in which MEYERS and JOHNSON, JJ., joined.
Appellant sought to present evidence of his diminished capacity as it affected his mental state at the time of the offense. The trial court ruled that any such evidence was inadmissible at the guilt stage. Appellant subsequently entered a voluntary plea of guilty conditioned upon his right to appeal the trial judge's "blanket" ruling.[1] The court of appeals held that the *892 trial court erred and remanded the case for further proceedings. The State now argues that appellant's offer of proof was insufficient to preserve error for appellate review. The majority, citing Texas Rule of Evidence 103(a)(2) and our decision in Warner v. State, 969 S.W.2d 1 (Tex.Crim. App.1998), agrees with the State. I respectfully dissent.
Rule 103(a)(2) provides that error may not be predicated upon a ruling which excludes evidence unless a substantial right of the party is affected and the substance of the evidence was made known to the court by offer of proof or was apparent from the context within which questions were asked. An offer of proof may be in question-and-answer form, or it may be in the form of a concise statement by counsel. Warner v. State, 969 S.W.2d at 2. An offer of proof to be accomplished by counsel's concise statement must include a reasonably specific summary of the evidence offered and must state the relevance of the evidence unless the relevance is apparent. Ibid. As the majority notes, the purposes of an offer of proof are: (1) to enable the trial court to reconsider its ruling in light of the evidence actually offered and (2) to enable the appellate court, if there is an appeal, to determine whether the trial court's ruling was erroneous and harmful. K. Broun, et al., McCormick on Evidence § 51 at 249 (6th ed. 2006).
After reviewing the record, I have no doubt that appellant satisfied Rule 103(a)(2)'s requirements. Given defense counsel's questioning of the venire, and given the subsequent colloquy between defense counsel, the State, and the trial court, it is quite clear that the trial court knew perfectly well, at the moment it ruled on defense counsel's proffer, that defense counsel intended to offer the testimony of a mental health expert[2] to the effect that appellant, because of schizophrenia,[3] had an abnormal understanding of reality[4] and, at the time he committed the capital murder in question, lacked the mental capacity to form the requisite mens rea of intentional or knowing.[5] In other words, defense counsel, in effect, gave a reasonably specific summary of the evidence he offered and he explained its relevance. An appellate court reviewing the record should be able to see this.
Admittedly, defense counsel could have been more deft when explaining the nature of the evidence that he offeredbut the information that he provided to the trial court, taken as a whole, was nonetheless clearly adequate for the purposes of Rule 103(a)(2). As I stated, the record reflects that the trial court understood perfectly well, as should an appellate court reviewing the record, what evidence defense counsel was offering. That is all that the rule requires.
In support of its holding, the majority cites our decision in Warner v. State, 969 S.W.2d 1, but that case is easily distinguishable on its facts. In Warner, the defendant, Michael Warner, who was on trial for aggravated kidnapping, aggravated assault, and arson, wanted to present evidence at the guilt stage that he had been a veteran of the Vietnam War, that he suffered from "post-traumatic stress disorder" (PTSD), that he had received counseling for that disorder, and that, because *893 of his PTSD, he had not had the specific intent necessary to commit the offenses of aggravated kidnapping and arson. Warner did not explain to the trial court, however, the nature of PTSD, how he intended to prove that he suffered from it, or how evidence of his PTSD would be relevant to the question of specific intent. We held that Warner had failed to make an adequate offer of proof under Rule 103(a)(2). In the instant case, in contrast, defense counsel made it quite clear to the trial court that he intended to offer proof from a mental health expert that appellant suffered from schizophrenia, a recognized mental disorder, and that appellant's schizophrenia distorted his view of reality and rendered him unable to form the requisite mens rea. The offer of proof in this case suffered from none of the defects that the offer of proof in Warner had.
I would affirm the judgment of the court of appeals. Because the majority does not do so, I respectfully dissent.
NOTES
[1]  See PENAL CODE § 19.03(a)(2).
[2]  160 S.W.3d 568 (Tex.Cr.App.2005).
[3]  "In all prosecutions for murder, the state or the defendant shall be permitted to offer testimony as to all relevant facts and circumstances surrounding the killing and the previous relationship existing between the accused and the deceased, together with all relevant facts and circumstances going to show the condition of the mind of the accused at the time of the offense." CODE CRIM. PROC. art. 38.36(a).
[4]  See R.App. P. 25.2(a)(2), 66 Tex. B.J. 167 (Tex.Cr.App.2003, amended 2007).
[5]  See Act of June 16, 1991, 72nd Leg., R.S., ch. 652, § 9, 1991 Tex. Gen. Laws 2394, 2395 (amended 2005) (current version at CODE CRIM. PROC. art. 37.071, § 1). "If a defendant is found guilty in a capital felony case in which the state does not seek the death penalty, the judge shall sentence the defendant to life imprisonment."
[6]  The Court of Appeals summarized the sole issue as "whether the defense may present evidence at the guilt/innocence phase of the trial to show that the defendant is afflicted with mental or physical impairments or abnormalities which bring into question whether he possessed the required state of mind at the time of the offense; in other words, whether a defendant's state of mind is such that it decreases his ability to formulate or possess the intent to commit a crime of the nature with which he is charged." Mays v. State, 223 S.W.3d 651, 653 (Tex.App.-Texarkana 2007).
[7]  Mays, 223 S.W.3d, at 654.
[8]  Ibid.
[9]  Ibid.
[10]  Ibid.
[11]  Id., at 654-55.
[12]  Id., at 655.
[13]  Ibid.
[14]  Jones v. State, 942 S.W.2d 1, 2 n. 1 (Tex.Cr. App.1997); accord Archie v. State, 221 S.W.3d 695, 698 (Tex.Cr.App.2007); Haley v. State, 173 S.W.3d 510, 515 (Tex.Cr.App.2005).
[15]  173 S.W.3d, at 515-17.
[16]  R. EVID. 103(a)(2).
[17]  Warner v. State, 969 S.W.2d 1, 2 (Tex.Cr. App.1998).
[18]  Ibid.
[19]  STEVEN GOODE, OLIN GUY WELLBORN III & M. MICHAEL SHARLOT, 1 TEXAS PRACTICE-GUIDE TO THE TEXAS RULES OF EVIDENCE: CIVIL AND CRIMINAL § 103.3 (1993).
[20]  Warner, 969 S.W.2d, at 1.
[21]  Ibid.
[22]  Ibid.
[23]  Id., at 1-2.
[24]  Id., at 2.
[25]  Ibid.
[26]  Ibid.
[27]  We do not reach the second ground of which we granted review: "Is error in the trial court's ruling during voir dire that it will not admit diminished capacity evidence at guilt-innocence automatically harmful when the appellant changes his plea to guilty as a result of the ruling?"
[1]  It is clear, in both the written and oral plea admonishments, that appellant pled guilty based upon the understanding that he could appeal from the trial judge's ruling. For example, the trial judge explicitly asked appellant, "[A]re you pleading guilty in order to request me to approve your plea agreement, which is a life sentence with the right to appeal on the issue of diminished capacity?" Appellant responded, "Yes, sir."
[2]  Court Reporter's Record, vol. 3, p. 87.
[3]  Court Reporter's Record, vol. 3, pp. 71-72, 78, 87.
[4]  Court Reporter's Record, vol. 3, p. 72.
[5]  Court Reporter's Record, vol. 3, pp. 78, 87.
