Justified True Belief

(●) From Justification to Warrant
Twentieth century epistemology was dominated by the “justified true belief” (JTB) model of knowledge. But after Gettier style counterexamples showed that justified true belief can still fall short of knowledge, many philosophers argued that something crucial was missing from the analysis. Alvin Plantinga’s notion of warrant is one influential attempt to supply that missing ingredient and to explain what, in addition to truth and belief, turns a mere true belief into knowledge. + Plantinga reserves the term “justification” for deontological or duty related notions (being blameless or responsible in believing), and uses “warrant” for the quality that actually makes a true belief into knowledge. On his view, a person can be justified yet still lack warrant if their faculties are not functioning in the right way or the environment is misleading.

(●) What Is Warrant?
Plantinga uses “warrant” for that special positive quality which, when added to truth and belief in sufficient degree, yields knowledge. True belief without warrant might be lucky, accidental, or unsupported. True belief with enough warrant is not just accidentally right; it is produced in the right way, by the right kinds of cognitive processes, in the right sort of situation.

(●) Proper Function and the Design Plan
On Plantinga’s account, a belief has warrant when it is produced by cognitive faculties (such as memory, perception, and reason) that are functioning properly, that is, according to a design plan, under conditions for which those faculties were designed. Proper function rules out malfunction (as in hallucination, severe cognitive damage, or pathological bias) and anchors knowledge in the normal operation of our intellectual equipment.

(●) The Right Environment
Proper function alone is not enough. Our faculties must also be operating in an environment similar to the one for which they were designed. Human vision, for example, is made for a world with normal lighting, ordinary distances, and reliable objects, not for distorted fun house mirrors or systematically deceptive laboratory setups. When the environment is too different from the one anticipated by the design plan, even properly functioning faculties may no longer reliably yield true beliefs.

(●) Aim at Truth and Sufficient Success
The design plan of our cognitive faculties is also aimed at truth. Under the right conditions, these faculties are successfully truth orientated. Warrant comes in degrees, depending on how well the faculties are functioning, how appropriate the environment is, and how truth conducive the processes are in that setting. When a belief is formed by properly functioning, truth aimed faculties in an appropriate environment and enjoys enough of this positive status, that belief is warranted.

(●) Maxi Environment and Mini Environment
Plantinga distinguishes between a broad “maxi environment” (the general kind of world in which our faculties are meant to operate) and the more specific “mini environments” in which particular beliefs are formed (for example, this specific room, this particular test, that specific instrument). A belief can be formed in the right kind of world overall yet still arise in a misleading local setup, a mini environment in which the usual methods are no longer reliably truth producing.

(●) Resolving Gettier Style Luck
Gettier examples show that justified true belief can occur in situations where the truth of the belief depends heavily on coincidence. Plantinga diagnoses these as cases where proper function and the broad environment may be fine, but the specific mini environment is epistemically hostile or deceptive. In such cases, the belief does not achieve the degree of warrant required for knowledge, even if it happens to be true and justified by the subject’s lights.

(●) Warrant and Knowledge
On Plantinga’s proposal, we can summarize knowledge as follows:
A person S knows that P if and only if:
1. S believes that P.
2. P is true.
3. S’s belief that P has enough warrant (is formed by properly functioning, truth aimed faculties, operating according to a good design plan, in an appropriate environment).
Warrant thus replaces bare “justification” as the crucial fourth factor that explains why some true beliefs are merely lucky while others rise to the level of genuine knowledge.