Keith Lehrer
Early Life and Education
Keith Lehrer, an influential figure in contemporary philosophy, was born on January 10, 1936, in the United States. His early education laid a strong foundation for his future academic pursuits. Lehrer attended Princeton University, where he earned his Bachelor of Arts degree in 1957. He continued his studies at Brown University, obtaining his Ph.D. in philosophy in 1960. His doctoral dissertation focused on the theory of knowledge, a field that would become central to his academic career.
Academic Career
Lehrer's academic career began at the University of Rochester, where he served as an assistant professor from 1960 to 1963. He then moved to the University of Minnesota, where he was promoted to associate professor in 1965 and full professor in 1969. In 1972, Lehrer joined the faculty at the University of Arizona, where he remained until his retirement. Throughout his career, Lehrer was a visiting professor at several prestigious institutions, including the University of Michigan and the University of California, Berkeley.
Philosophical Contributions
Epistemology
Lehrer is best known for his work in epistemology, the study of knowledge. He developed a theory known as "coherentism," which posits that beliefs are justified if they cohere with a system of beliefs. This theory stands in contrast to foundationalism, which argues that certain basic beliefs provide the foundation for all other beliefs. Lehrer's coherentism emphasizes the importance of the coherence of an entire belief system rather than the justification of individual beliefs.
The Gettier Problem
Lehrer made significant contributions to the Gettier problem, a challenge to the traditional definition of knowledge as "justified true belief." The Gettier problem, introduced by Edmund Gettier in 1963, presents scenarios where individuals have justified true beliefs that do not constitute knowledge. Lehrer proposed solutions to this problem by refining the conditions under which a belief can be considered knowledge, emphasizing the importance of defeasibility and the role of a "justification condition."
Personal Identity
In addition to his work in epistemology, Lehrer explored issues related to personal identity. He examined the nature of self and the continuity of personal identity over time. Lehrer's approach to personal identity is rooted in psychological continuity, arguing that personal identity is maintained through the continuity of psychological states and memories.
Aesthetics
Lehrer also contributed to the field of aesthetics, the study of beauty and art. He explored the nature of aesthetic experience and the criteria for evaluating works of art. Lehrer's work in aesthetics often intersects with his epistemological theories, as he examines how aesthetic judgments can be justified and how they fit into a coherent belief system.
Major Works
Lehrer's prolific writing includes numerous books and articles that have had a lasting impact on the field of philosophy. Some of his most notable works include:
- "Knowledge" (1974) - This book presents Lehrer's coherentist theory of knowledge and addresses the Gettier problem.
- "Theory of Knowledge" (1990) - An expanded exploration of epistemological issues, including the nature of justification and the structure of belief systems.
- "Self-Trust: A Study of Reason, Knowledge, and Autonomy" (1997) - In this work, Lehrer examines the role of self-trust in knowledge acquisition and personal autonomy.
- "Art, Self, and Knowledge" (2012) - A collection of essays that explore the intersections of aesthetics, epistemology, and personal identity.
Influence and Legacy
Keith Lehrer's contributions to philosophy have influenced a wide range of fields, including epistemology, aesthetics, and personal identity. His coherentist theory of knowledge has been the subject of extensive debate and analysis, shaping contemporary discussions on the nature of justification and belief. Lehrer's work continues to be studied and referenced by philosophers and scholars around the world.