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Your search for Who said I think therefore I am returned the following results:

Rene Descartes

Rene Descartes stated “I think therefore I am”, which is the very thought perceived as the foundation of all knowledge.

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French philosopher René Descartessaid

In answer to this question, French philosopher René Descartessaid, “I think, therefore I am” (Meditations, 7:140).

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Philosopher René Descartes (1596-1650), also a Roman Catholic,

Philosopher René Descartes (1596-1650), also a Roman Catholic, famously coined the phrase ‘I think, therefore I am.’

Renee Descartes

You may have heard of Renee Descartes, a philosopher who famously said "I think therefore I am", ushering in an era of human rationality known as the Enlightenment.

‘Cogito ergo sum’

‘Cogito ergo sum,’ (I think, therefore, I am) is Descartes’ iconic statement of 1632.

a truncated form of a phrase less popular (but nonetheless popularized) by René Descartes

The phrase you are referring to, 'I think, therefore I am' is a truncated form of a phrase less popular (but nonetheless popularized) by René Descartes, '

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