Susan Haack

Quick Facts

• Name: Susan Haack
• Lived: 1945-2026
• Born in: Buckinghamshire, England
• Main places: University of Warwick; University of Miami
• Main fields: epistemology, logic, philosophy of science, pragmatism, philosophy of law
• Main labels: Pragmatism, Analytic Philosophy, Philosophy of Science
• Best known for: foundherentism, a theory of evidence and justification
• Main works: Deviant Logic; Philosophy of Logics; Evidence and Inquiry; Defending Science - Within Reason; Evidence Matters

The Big Question

How can inquiry be rational if we have no absolutely certain starting point?

Haack's answer was that good belief works more like solving a crossword than building a tower. Experience gives us clues. Other beliefs cross-check the answer. Neither part is enough by itself.

In One Minute

Susan Haack was a British-American philosopher who worked across logic, evidence, science, pragmatism, and law. Her best-known view is foundherentism. The name is ugly on purpose: it joins foundationalism and coherentism while rejecting the bad parts of both.

Foundationalism says knowledge needs basic beliefs that support the rest. Coherentism says beliefs are justified by fitting together in a whole system. Haack thought pure foundationalism makes some beliefs look magically secure, while pure coherentism can become a closed circle. Her alternative says evidence has both parts: experience anchors inquiry, and coherence with the rest of what we know helps test it.

The same middle path shaped her philosophy of science. She defended science against relativism, the view that truth is just what a group accepts, but also attacked scientism, the habit of treating science as the only serious kind of knowledge or as a magic answer machine.

What They Taught

Haack taught that inquiry is the ordinary human work of trying to find out what is true. It means asking a question, looking for evidence, checking alternatives, and being willing to change your mind when the evidence turns.

Her central problem was justification. A belief is justified when it has enough support to deserve acceptance. If you believe the bridge is unsafe because an engineer found cracks, that is different from believing it because you had a bad feeling. The first belief is answerable to evidence.

Haack rejected the demand for perfect certainty. Fallibilism means that even our best-supported beliefs can still turn out false. It is not skepticism. It says knowledge grows by correction.

Foundherentism is Haack's answer to two older theories of knowledge. Foundationalism tries to stop the regress of reasons by finding basic beliefs. The risk is arbitrariness: why are these beliefs basic? Coherentism says beliefs support one another inside a system. The risk is circularity: a story can hang together and still be fantasy.

Haack's famous example is a crossword puzzle. A clue gives you direct evidence for an answer, but the answer also has to fit the crossing entries. Empirical belief works the same way. Observation matters, but observation is checked against background knowledge.

This view also explains her philosophy of science. Science is not a single mechanical method that guarantees truth. It is a refined form of everyday empirical inquiry. Scientists use instruments, experiments, mathematics, statistics, peer criticism, replication, and background theory to improve the normal habits of checking and correcting beliefs.

Haack was a realist. Realism means that there is a world independent of what we believe about it. Evidence matters because reality pushes back. A drug either helps patients or it does not. But she was also a pragmatist: she thought ideas have to be understood through their role in inquiry and practice.

Her pragmatism is closest to Charles Sanders Peirce. Peirce treated inquiry as a disciplined search for truth, not as whatever happens to be useful. Haack used that Peircean spirit against two opposite mistakes: cynics who reduce science to politics or fashion, and enthusiasts who talk as if science can answer every serious question by itself.

Her work on law put these ideas under pressure. Courts often need answers now, while science often moves slowly. Courts ask case-specific questions, while science usually gives general results with degrees of uncertainty. Haack argued that judges and lawyers need a better grasp of evidence, expertise, error, and the limits of scientific testimony.

Key Ideas With Examples

• Foundherentism: Haack's theory that justification depends both on experiential evidence and on how well a claim fits with other warranted beliefs. Example: a witness report is like a crossword clue; records, timing, and physical evidence are like crossing entries.
• Empirical evidence: information from experience that bears on whether a claim is true. A thermometer reading, a lab result, a dated letter, or a repeated observation can count as evidence, if it is gathered and interpreted carefully.
• Justification or warrant: the degree to which a belief deserves acceptance. A weather forecast can be well supported even if it later misses a sudden storm.
• Fallibilism: the view that any human belief can be mistaken. This does not make inquiry pointless. It makes checking, criticism, and correction necessary.
• Coherence: the way a claim fits with other things we have reason to believe. If a new historical claim conflicts with dates, letters, and independent records, the conflict lowers its credibility unless there is a good explanation.
• Scientism: an exaggerated view of science. It treats science as the only serious route to understanding, or treats scientific language as automatically superior. Haack thought this damages both science and philosophy.
• Anti-scientific cynicism: the opposite exaggeration. It treats science as mere politics, rhetoric, funding pressure, or social power. Haack thought this ignores how evidence, testing, and criticism can make inquiry genuinely better.
• Legal evidence and expert testimony: information used in court, often from specialists. Haack argued that courts should ask whether an expert's claim is well supported, not just whether it wears the label "scientific."
• Analytic clarity: the habit of making distinctions, arguments, and terms explicit. Haack used this style, but she resisted making philosophy into a narrow technical game cut off from science, law, literature, and public life.

Major Works

• Deviant Logic (1974) and Philosophy of Logics (1978): early books on classical and alternative logics. They ask what logic is for, what validity means, and how formal systems connect to philosophical questions.
• Evidence and Inquiry (1993): Haack's main book in epistemology. It develops foundherentism and criticizes rival views, including strict foundationalism, coherentism, reliabilism, naturalized epistemology, and anti-epistemology.
• Manifesto of a Passionate Moderate (1998): essays defending independent judgment against fashionable extremes. Haack argues for plain speech, intellectual honesty, and resistance to both dogmatism and relativism.
• Defending Science - Within Reason (2003): her major work in philosophy of science. It argues that science is one of our best forms of inquiry, while warning against both scientism and cynical attacks on science.
• Pragmatism, Old and New (2006): an anthology and interpretation of pragmatism. Haack contrasts classical pragmatists such as Peirce, William James, and John Dewey with later versions she sees as too loose about truth.
• Evidence Matters (2014): a collection on science, proof, and truth in law. It applies her epistemology to expert testimony, peer review, causation, forensic evidence, and the courtroom search for facts.
• Scientism and Its Discontents (2017): a short book attacking the overextension of science. Haack's target is not science itself, but the idea that scientific prestige can replace careful thinking.

Why It Matters

Haack matters because she gives a sober middle position in debates that often become slogans. Against relativism, she says evidence is real and inquiry can improve. Against scientism, she says science is fallible, human, and limited. Against skepticism, she says we do not need certainty to have warranted belief.

Her legal work matters because public decisions often depend on expert knowledge. Courts, policy debates, and media arguments all need ways to separate better-supported claims from weaker ones without pretending that evidence is simple.

She also matters as a style of philosopher. She combined Analytic Philosophy's concern for precision with Pragmatism's concern for inquiry in the real world.

Proponents, Critics, and Opponents

Haack's most important philosophical ancestor is Charles Sanders Peirce. From him she takes fallibilism, realism, the idea of inquiry as a search for truth, and distrust of easy relativism. She is also close to the classical pragmatist line running through William James and John Dewey, though she is more Peircean than Rortyan.

She belongs partly to Analytic Philosophy. Her early work in logic and her demand for clear distinctions show that background. She learned from the clarity prized by philosophers such as A. J. Ayer, but she rejected the narrow positivist habit of treating meaning and evidence as if they could be reduced to a simple verification rule.

W. V. O. Quine is an important comparison. Haack accepted some holist pressure: beliefs are tested in connection with other beliefs. But she resisted any version of naturalized epistemology that seems to drop the normative question, "What makes this belief reasonable?"

Her sharpest pragmatist opponent was Richard Rorty. Rorty treated truth and objectivity more lightly than Haack thought a serious pragmatist should. She argued that Peircean pragmatism is not a license to replace truth with conversation, solidarity, or usefulness.

Critics of Haack have pressed foundherentism from both sides. Some coherentists think she gives experience too much special weight. Some foundationalists think her view is still a kind of softened foundationalism. Laurence BonJour and Peter Tramel are useful names here. In law, some critics also think her attacks on courtroom science and expert testimony can underplay how hard judges' practical gatekeeping job is.

Related Pages

• Charles Sanders Peirce
• A. J. Ayer
• W. V. O. Quine
• Richard Rorty
• William James
• John Dewey
• Pragmatism
• Philosophy of Science
• Analytic Philosophy