Date: c. 501 B.C.

"For souls it is death to become water, and for water death to become earth. Water comes into existence out of earth, and soul out of water."

— Heraklitus (fl. 504-1 BCE)

Date: c. 501 B.C.

"One would never discover the limits of soul, should one traverse every road--so deep a measure does it possess."

— Heraklitus (fl. 504-1 BCE)

Date: c. 501 B.C.

"A dry gleam of light is the wisest and best soul."

— Heraklitus (fl. 504-1 BCE)

Date: 380-360 B.C.

"So this journey which is now ordained for me carries a happy prospect for any other man also who believes that his mind has been prepared by purification."

— Plato (427 BC - 347 BC)

Date: 380-360 B.C.

"Because every pleasure or pain has a sort of rivet with which it fastens the soul to the body and pins it down and makes it corporeal, accepting as true whatever the body certifies."

— Plato (427 BC - 347 BC)

Date: 380-360 B.C.

"The body is held together at a certain tension between the extremes of hot and cold, and dry and wet, and so on, and our soul is a temperament or adjustment of these same extremes, when they are combined in just the right proportion."

— Plato (427 BC - 347 BC)

Date: 380-360 B.C.

"[T]here is in every soul an organ or instrument of knowledge that is purified and kindled afresh by such studies when it has been destroyed and blinded by our ordinary pursuits, a faculty whose preservation outweighs ten thousand eyes, for by it only is reality beheld."

— Plato (427 BC - 347 BC)

Date: c. 370-365 B.C.

"The soul through all her being is immortal, for that which is ever in motion is immortal; but that which moves another and is moved by another, in ceasing to move ceases also to live."

— Plato (427 BC - 347 BC)

Date: 360-355 B.C.

"Imagine, then, for the sake of argument, that our minds contain a block of wax, which in this or that individual may be larger or smaller, and composed of wax that is comparatively pure or muddy, and harder in some, softer in others, and sometimes of just the right consistency."

— Plato (427 BC - 347 BC)

Date: 360-355 B.C.

"Let us call it the gift of the Muses' mother, Memory, and say that whenever we wish to remember something we see or hear or conceive in our own minds, we hold this wax under the perceptions or ideas and imprint them on it as we might stamp the impression of a seal ring."

— Plato (427 BC - 347 BC)