''Katalepsis'' (, "grasping") is a term in

Stoic Stoic may refer to: * An adherent of Stoicism Stoicism is a school of Hellenistic philosophy that flourished in ancient Greece and Rome. The Stoics believed that the universe operated according to reason, ''i.e.'' by a God which is immersed i ...

philosophy for a concept roughly equivalent to modern '' comprehension''. To the Stoic philosophers, ''katalepsis'' was an important premise regarding one's state of mind as it relates to grasping fundamental philosophical concepts, which was followed by the assent, or adherence to the truth thus understood. According to the

Stoics Stoicism is a school of Hellenistic philosophy that flourished in ancient Greece and Rome. The Stoics believed that the universe operated according to reason, ''i.e.'' by a God which is immersed in nature itself. Of all the schools of ancient ...

, the

mind The mind is that which thinks, feels, perceives, imagines, remembers, and wills. It covers the totality of mental phenomena, including both conscious processes, through which an individual is aware of external and internal circumstances ...

is constantly being bombarded with impressions (''

phantasiai In Hellenistic philosophy, ''phantasiai'' (φαντασίαι) are pieces of information received from sense experience. The Pyrrhonists, Epicureans, and Stoics use the term to refer to information received through the senses and arising in th ...

''). Some of these impressions are true and some false. Impressions are true when they are truly affirmed, false if they are wrongly affirmed.

Cicero Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, orator, writer and Academic skeptic, who tried to uphold optimate principles during the political crises tha ...

relates that

Zeno Zeno may refer to: People * Zeno (name), including a list of people and characters with the given name * Zeno (surname) Philosophers * Zeno of Elea (), philosopher, follower of Parmenides, known for his paradoxes * Zeno of Citium (333 – 264 B ...

would illustrate ''katalepsis'' as follows:

He would display his hand in front of one with the fingers stretched out and say "A visual appearance is like this"; next he closed his fingers a little and said, "An act of assent is like this"; then he pressed his fingers closely together and made a fist, and said that that was comprehension (and from this illustration he gave to that process the actual name of ''katalepsis'', which it had not had before); but then he used to apply his left hand to his right fist and squeeze it tightly and forcibly, and then say that such was knowledge, which was within the power of nobody save the wise man.

''Katalepsis'' was the main point of contention between the Stoics and the two schools of

philosophical skepticism Philosophical skepticism (UK spelling: scepticism; from Ancient Greek, Greek σκέψις ''skepsis'', "inquiry") is a family of philosophical views that question the possibility of knowledge. It differs from other forms of skepticism in that ...

during the

Hellenistic period In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the R ...

: the

Pyrrhonists Pyrrho of Elis (; ; ) was a Greek philosopher of Classical antiquity, credited as being the first Greek skeptic philosopher and founder of Pyrrhonism. Life Pyrrho of Elis is estimated to have lived from around 365/360 until 275/270 BCE. Pyr ...

and the Academic Skeptics of

Plato's Academy The Academy (), variously known as Plato's Academy, or the Platonic Academy, was founded in Athens by Plato ''circa'' 387 BC. The academy is regarded as the first institution of higher education in the west, where subjects as diverse as biolog ...

. These Skeptics, who chose the Stoics as their natural philosophical opposites, eschewed much of what the Stoics believed regarding the

human mind The mind is that which thinks, feels, perceives, imagines, remembers, and wills. It covers the totality of mental phenomena, including both conscious processes, through which an individual is aware of external and internal circumstances, ...

and one's methods of understanding greater meanings. To the Skeptics, all perceptions were acataleptic, i.e. bore no conformity to the objects perceived, or, if they did bear any conformity, it could never be known.George Henry Lewes (1863), ''The biographical history of philosophy'', Volume 1, p. 297

Notes

{{Ancient Greek philosophical concepts Concepts in ancient Greek epistemology Concepts in ancient Greek philosophy of mind Stoicism