In the

philosophy of mind Philosophy of mind is a branch of philosophy that studies the ontology and nature of the mind and its relationship with the body. The mind–body problem is a paradigmatic issue in philosophy of mind, although a number of other issues are add ...

, Leibniz's gap is the problem that thoughts cannot be observed or perceived solely by examining

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

properties, events, and processes. Here the word "gap" is a

metaphor A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are often compared wi ...

of a subquestion regarding the

mind–body problem The mind–body problem is a philosophical debate concerning the relationship between thought and consciousness in the human mind, and the brain as part of the physical body. The debate goes beyond addressing the mere question of how mind and bo ...

that allegedly must be answered in order to reach a more profound understanding of

consciousness Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...

and emergence. A

theory A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be ...

that could correlate brain phenomena with psychological phenomena would "bridge the gap". The term Leibniz's gap was coined by Robert Cummins and was named after

Gottfried Leibniz Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of mathem ...

, who first presented the problem in his work ''

The Monadology The ''Monadology'' (french: La Monadologie, 1714) is one of Gottfried Leibniz's best known works of his later philosophy. It is a short text which presents, in some 90 paragraphs, a metaphysics of simple substances, or '' monads''. Text Dur ...

'' in 1714. Leibniz's passage describing the gap goes as follows: The problem according to Leibniz is that there is a gap between concepts of modern neuroscience and those that we use to describe the brain such as "thought", "feeling", and "perception". This means that the physical observation of the brain yields data in the wrong vocabulary even if we are convinced that the mind is the brain. Leibniz himself sought to bridge the gap by introducing monads to explain the existence of immaterial, eternal souls. Leibniz's gap, however, applies to materialism and dualism alike. This brought late 19th century scientists to conclude that psychology must build on

introspection Introspection is the examination of one's own conscious thoughts and feelings. In psychology, the process of introspection relies on the observation of one's mental state, while in a spiritual context it may refer to the examination of one's sou ...

; thus introspectionism was born.

Computationalism In philosophy of mind, the computational theory of mind (CTM), also known as computationalism, is a family of views that hold that the human mind is an information processing system and that cognition and consciousness together are a form of c ...

seeks to answer the problem proposed by Leibniz's gap through functional analysis of the brain and its processes. There is the position that functionalism could address the gap since it allows something to be described in terms of what it does without explaining how it does it or identifying the physical form it takes. Today, however, Leibniz's gap is still in wide use in scientific debate as the mind body problem that remains unsolved.

References

Arguments in philosophy of mind Cognitive science Philosophical analogies Gottfried Wilhelm Leibniz {{philo-concept-stub

See also

References