I think; therefore I am

Cogitō ergo sum

René Descartes Méditations sur la philosophie première (1641).

L. cogitō
To think, ponder, consider, plan

je pense donc je suis

Fr. penser
To think, reckon; guess, imagine; reflect; realize, figure; wonder
I wonder (pense) what Descartes meant. I have no idea if Descartes translated his own work into Latin, but the original is in French, which is significant because it was one of the first, if not the first, philosophical treatise written in the vernacular. The English saying, “I think, therefore I am,” comes from the Latin translation (1644). To me, I am certain of my existence because I am aware of my own existence. What I think can be erroneous, as it usually is, but being aware of myself is without question. The difference in meaning between I think, cogitō, and pense is notable. The connotations are different. I believe that Descartes really meant wonder, realize, even imagine. These meanings are not the strenuous mental exercise that is thinking.

People who dismiss Descartes as nonsense have either not read the Meditations, or they have not understood him.

In the context of Philosophy, reason is not a natural activity but one that takes a good deal of study and practice. Rhetoric is the academic discipline that applies abstract reasoning to practical matters. In every day speech, rhetoric usually refers to obfuscation, but in actually it is anything but. Rhetoric conveys meaning as close to perfectly as is possible, given the clumsy nature of language.

Sometime in the future, I plan to convey my thoughts on how another French philosopher, Jean-Paul Sartre, in his treatise Being and Nothingness (also written in French, 1943), builds on Descartes.

Reality

What is Reality, anyway?

REALITY: What we perceive as reality is a tiny detail from the field of possibilities surging around us which our nervous system has realized through computation. If all reality is a computation from possibilities, then "reality" is a threshold value. (Vilém Flusser's key words, compiled from book and magazine publications, lectures, and interviews. Edited by Andreas Müller-Pohle and Bernd Neubauer)

REALITY is considered as an infinite space and time, which we conceive as the complex physical actuality that surrounds us and constantly changes. (Radoš Šumrada: The Internal and External Views of Cadastral Information Systems by Erik Stubkjær.

REALITY: Has to do with agreement (or lack thereof). It is the agreed-upon apparency of existence. A reality is any data that agrees with the person's perceptions, way of thinking and education. Reality is one of the components of understanding. Reality is what is. (The Road to Clear, Clearbird Publishing.)

REALITY: the quality or state of being real. (Merriam-Webster Online Dictionary).

REALITY: The quality of being real or having an actual existence. (Oxford English Dictionary)

Well, it seems that the dictionaries are useless for this quest. The others are closer to what I mean when I say that "Reality is a human construct." That is the concept of maya. Numbers, pictures, language, etc. are all human constructs. They are all true only to the extent that humans agree they are. Although he is talking specifically about science, Thomas Kuhn presents a "concrete" example: The Ptolemaic Universe was "reality" for centuries, if not millennia. Along comes Copernicus, and “reality” changes dramatically. Now, Copernicus is real and Ptolemy is myth. My point is that the “reality” of both Ptolemy and Copernicus depends entirely upon a general agreement among humans that both these models, in their time, were perceived as “real.” String Theory promises to describe a new “reality,” making Copernicus a myth too.

Plato describes “reality” as existing only in the “ideal forms.” Kant describes “reality” as existing only in the “noumenal realm.” The Bhagavad-Gita describes “reality” as what “always was and cannot ever be destroyed.”

“Reality” is a “field of possibilities,” not an absolute. Reality isn’t real.