dissenting.
It is time to restore' the law of claim construction to a more apt wisdom and more usable simplicity. The only issue in this case is the construction of the phrase “inhibitor or activator of a protein.” My colleagues’ approach to construction is based on confusing recent pronouncements of panels of this court, contravening earlier statements of precedent, thus adding to the confusion.
I
The panel majority propounds the rule that the “plain and ordinary meaning of the claim language” should be used to define the scope of the claims unless the inventor “has explicitly disclaimed or clearly disavowed this meaning.” Maj. op. at 1351-1352. The panel majority states that absent such disclaimer, claims are “inimical to any narrower construction.” Maj. op. at 1352. Precedent is exactly contrary: a claim is “inimical” to any broader construction than the invention set forth in the specification, and reliance on dictionaries, even technical dictionaries, without due consideration of the context of the invention may lead to “absurd results”:
Indiscriminate reliance on definitions found in dictionaries can often produce absurd results. Words are used in many senses and often have diametrically opposed meanings, depending upon *1357the sense in which they are used. One searching for the dictionary definitions of ‘effectively’ or ‘effect’ will find among the numerous definitions listed many which are indisputably inapplicable to the instant use of the word ‘effectively.’ But the words in which a claim is couched may not be read in a vacuum. One need not arbitrarily pick and choose from the various accepted definitions of a word to decide which meaning was intended as the word is used in a given claim. The subject matter, the context, etc., will more often than not lead to the correct conclusion.
Liebscher v. Boothroyd, 46 C.C.P.A. 701, 258 F.2d 948, 951 (1958). See also e.g., Netword, LLC v. Centraal Corp., 242 F.3d 1347, 1352 (Fed.Cir.2001) (“The claims are directed to the invention that is described in the specification; they do not have meaning removed from the context from which they arose.”); Toro Co. v. White Consol. Indus., Inc., 199 F.3d 1295, 1299 (Fed.Cir.1999) (“[W]ords of ordinary usage must nonetheless be construed in the context of the patent documents. Thus the court must determine how a person of experience in the field of this invention would, upon reading the patent documents, understand the words used to define the invention.”); Renishaw PLC v. Marposs Societa’ per Azioni, 158 F.3d 1243, 1250 (Fed.Cir.1998) (“[A] common meaning, such as one expressed in a relevant dictionary, that flies in the face of the patent disclosure is undeserving of fealty.... [T]he interpretation to be given a term can only be determined and confirmed with a full understanding of what the inventors actually invented and intended to envelop with the claim.”). Claims to an invention that is not described in the specification are an anachronism. Many inventions concern complex and detailed technology, and the terse style of the patent claim is not a replacement for the elaboration in the written description. The claims are the concluding portion of the specification, and their statutory function is “particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.” 35 U.S.C. § 112. A claim has no meaning out of the context of the invention that is described, enabled, and prosecuted.
This case again illustrates the conflict generated in the court’s recent jurisprudence of claim construction. The panel majority reinforces the recently created dominance of general definitions, wherein the court created a “heavy presumption” in contravention of precedent. It is an established rule of the construction of legal documents that technical terms are presumed to have the meaning of the technical field of the document, not a “general meaning.” Technical terms take their meaning from the technology and context in which they are used, not from general usages of the same word. Thus terms in patent claims are understood in the technical/scientific context of the specification; the presumption is that they have their technical meaning, not a general meaning.
This same interpretive rule applies to statutes, contracts, deeds, patents, and other legal documents. See, e.g., 2A Norman Singer, Sutherland Statutory Construction § 47:29 (6th ed. 2000) (“In the absence of legislative intent to the contrary, or other overriding evidence of a different meaning, technical terms or terms of art used in a statute are presumed to have their technical meaning. If a term is connected with and used with reference to a particular trade, the term will have the meaning given [by] experts in the particular trade.”) (footnotes omitted).
It is curious indeed to announce a “heavy presumption” that the meaning of a term in a patent claim is unencumbered by the specification, and to place a “heavy burden” on overcoming that presumption. *1358Such a presumption dissociates the term from the invention described, enabled, and prosecuted by the inventor, and places an unnecessary burden on the inventor who wants simply to restore the meaning that the inventor and the examiner, and others in the field of the invention, clearly understand. I thus state my respectful disagreement with the panel’s reinforcement of the distortions that have entered this court’s jurisprudence. The written description is not an also-ran in claim construction, as the panel states; it is the primary resource in understanding the claims.
Patent claims are stated in words, and words can have a non-technical as well as a technical meaning. The words “inhibit” and “activate” are good examples of such words, invoking the rule that their specific meaning is derived from the field of their usage, upon inspection of the patent specification and the prosecution history. See, e.g., Toro, 199 F.3d at 1299-1300 (“In judicial ‘claim construction’ the court must achieve the same understanding of the patent, as a document whose meaning and scope have legal consequences, as would a person experienced in the technology of the invention.’ ”), further appeal, 266 F.3d 1367 (Fed.Cir.2001). The Toro court recognized that “dictionary definitions of common words are often less useful than the patent documents themselves in establishing the usage of ordinary words in connection with the claimed subject matter.” Id. at 1300 (each party relying on a different dictionary definition that favored its position).
The rule is that claims are viewed and understood in light of the specification, of which they are a part. See, e.g., Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.3d 1473, 1478 (Fed.Cir.1998) (“The best source for understanding a technical term is the specification from which it arose, informed, as needed, by the prosecution history.”). If there is a “presumption” in claim construction, it is that a claim term has the meaning ascribed by the patent documents. It is incorrect to impose the obverse “heavy presumption” that the dictionary definition dominates and all inapplicable variants must be expressly disclaimed. The role of dictionaries and treatises is to educate the non-technical judge in understanding what the inventor and the examiner understood, not to impose a new evidentiary presumption and not to enlarge the patented invention beyond that set forth by the inventor. The words of patent claims have the meaning and scope with which they are used in the specification and the prosecution history.
It is also incorrect to hold that words in claims are broader in meaning than their usage in the specification, simply because a dictionary definition may not contain the limitations of the specification. It is imprecise to state that claims are not limited by “a narrow specification” unless the inventor expressly so limits them, maj. op. at 1352, for the specification always limits the claims. The claims are part of the specification; their role is to point out what is covered by the patent, not to broaden the text. See, e.g., Dow Chemical Co. v. Sumitomo Chemical Co., 257 F.3d 1364, 1378 (Fed.Cir.2001) (claim scope is limited to the meaning set forth in the patent documents).
The panel thus perpetuates a distortion of the construction of patent documents, contrary to precedent and defeasible of the critical need for stability and predictability in the system of patents.
II
This case turns on whether the claim clause “inhibitor or activator of a protein” requires direct interaction with the protein. My colleagues on this panel rely on a general understanding of the word *1359“specificity” to decide that the claims cover all forms of indirect interactions and are therefore invalid. The specification, on its face, can support either theory, but does not support the majority’s ruling that Housey’s proposed limitation of the term “inhibitor or activator” is “inimical” to the majority’s proposed “plain meaning” taken from general dictionaries. It is noteworthy that the majority’s proposed “plain meaning” differs from the specification’s statement of the invention.
The patent documents state that the invention concerns “direct modulation,” and that the prior art shows primarily “indirect modulation” of intermediate agents. The defendants dispute this statement. The patentee buttresses its position with selections from the specification, for example:
Thus, this work establishes, for the first time, the fact that stable overproduction of a protein in mammalian cells can result in a novel cellular phenotype(s) ... which can be directly modulated by chemical agents which interact with the protein.
’281 patent, col. 18, lines 30-36:
In particular, it is concerned with a method of screening for substances which specifically inhibit or activate a particular protein, especially in a manner apparent to the naked eye.
’281 patent, col. 1, lines 10-12. The defendants cite other, broader statements.
Both sides cite dictionaries and technical treatises that support their respective positions, Housey citing the Textbook of Receptor Pharmacology 123 (John C. Foreman & Torben Johansen eds., 1996) for its statement that:
An all-important consideration in binding studies is the extent to which the measured binding of a radioligand represents association with the receptor or other site of interest. In functional studies there is no difficulty, the response can only be elicited by the binding of an agonist [activator] to the receptor and for an antagonist [inhibitor] to inhibit the response to an agonist it must also bind to the receptor (or a site coupled to it). Invariably, in binding studies there is uptake of the radioli-gand by other tissue components (unless, of course, binding to a purified, soluble protein is under investigation). The binding to the receptor is normally termed specific binding, whereas the binding to nonreceptor tissue components is referred to as nonspecific binding.
The prosecution of the '007 patent referred to the specificity of direct binding; for example, Dr. Housey told the examiner:
Substances so identified or characterized using the teachings of the Housey patents will be found to interact directly with the target protein itself and/or with other proteins which the target protein also interacts in the form of dimeric or multimeric complexes. In this fashion, the approach disclosed in the Housey patents provides a specificity between a target protein and its attendant biochemical pathways within the cell that is impossible to achieve with other assay systems.
Declaration of Gerard M. Housey under 37 C.F.R. § 1.132 at ¶ 14, October 22, 1996.
In a related proceeding involving these patents, Bayer’s expert Dr. Griffin submitted a declaration to the court stating that the terms “specific” and “specifically” are used to characterize a substance that binds to a target protein. Declaration of Dr. James Griffin at 1, June 7, 2002, Bayer AG v. Housey Pharms., Inc., No. 01-148 (D. Del. filed March 6, 2001). On the other hand, Bayer’s expert Dr. Roninson provided evidence during a deposition as follows:
*1360Q. As a scientist, when you see the term “specific inhibitor,” do you not understand that to mean substance is binding to the protein?
A. No, I don’t.
Deposition of Igor B. Roninson at 42, June 19, 2002, Bayer AG v. Housey Pharms., Inc., No. 01-148 (D. Del. filed March 6, 2001). But Bayer’s expert Dr. Fields stated that “one aspect of being a specific activator or inhibitor is that it binds directly to that protein of interest....” Deposition of Alan P. Fields at 91, July 2, 2002, Bayer AG v. Housey Pharms., Inc., No. 01-148 (D. Del. filed March 6, 2001). And defendants’ expert Dr. Silverstein stated before the district court in this litigation that “[although ... [drug discovery] programs may include cell-based assays, for the reasons stated above, they must include cell-free assays in order to determine whether or not there is a direct interaction between the test substance and the protein of interest.” Declaration of Professor Saul J. Silverstein at ¶ 22, August 28, 2002, Housey Pharms., Inc. v. Astrazeneca UK Ltd., No. 01-CV-401 (D.Del. November 27, 2002).
This conflicting expert testimony requires resolution by the court, but such resolution must be consistent with the subject matter that was invented, described and enabled. Reliance on dictionaries does not achieve this purpose. In addition, when it is reasonable to do so, claims should be construed so as to preserve their validity. See Wang Labs. Inc. v. America Online Inc., 197 F.3d 1377, 1382 (Fed.Cir.1999) (claims should be construed, when reasonably possible, to sustain their validity).
On correct guidance of the principles of claim construction, I would remand for resolution of conflicting scientific evidence, and re-determination of the meaning and scope of the correctly construed claim.