Quote Of The Day By René Descartes: 'In Order To Seek Truth, It Is Necessary...'

French philosopher René Descartes is thought of as the "father of modern philosophy." Born in 1596 in La Haye en Touraine, Descartes was pressured by his family to study law and got his degree at the age of 22. He never practiced law, though, and instead found himself focused on mathematics, reason, and philosophy, and how an understanding of math can help one understand life. Descartes' logic-centered philosophy was very different from the perspectives of past thinkers; in fact, it encouraged people to doubt everything they thought they knew and go back to square one.

The starting point of Descartes' method can be summed up in one of the most famous quotes from any philosopher: "I think, therefore I am," or "cogito, ergo sum." For Descartes, the only way to know the world was to deconstruct it and start from scratch, interrogating everything for certainty. It's difficult to know anything for sure when you doubt everything, though. However, the very act of doubting, of thinking, means that you must exist. In many ways, this line of thinking was the first building block of modern philosophy.

While Descartes' views may be centuries old, his perspectives on life, epistemology, metaphysics, mathematics, and what it means to be human are just as important today as they ever were. That's why one of Descartes' many thought-provoking philosophical quotes, one that's related in many ways to his most famous line, is today's quote of the day.

In his 1644 book "Principles of Philosophy," René Descartes wrote, "In order to seek truth, it is necessary once in the course of our life, to doubt, as far as possible, of all things." This notion is a key component of Descartes' famous belief system, and one of the founding aspects of the scientific method. It's applicable outside of science and philosophy, too, since facing everything you learn with a bit of doubt is the only way to think critically and really get to the truth.

As we grow up, we are taught all sorts of things about life and how the world works. Yet, simply believing everything we are told is no way to really discover anything about our lives and how we see the world. In order to think critically and develop a personality of our own, we have to question everything.

Methodic doubt, or radical skepticism, was a pillar of René Descartes' beliefs, to the extent that it is now often known as Cartesian doubt. It meant actively abandoning all preconceived notions about life, death, and humanity and pursuing a blank slate to use as the basis for your understanding of the world. To really accomplish this, it's vital to introduce doubt into all facets of learning and to interrogate everything you are told.

In some ways, society teaches us that there are a few ways to live and think and that following the path set out for us is the way to achieve a happy and fulfilling life. It's easy to go through life never questioning what we hear or why society functions the way it does. Just because we read something online or in the paper, hear it on a podcast or in a conversation, or see it on TV or a billboard doesn't mean it's true. Having a healthy dose of skepticism, even if it isn't necessarily radical, is the best way to find something you can actually believe in.

• "I think, therefore I am"
• "It is not enough to have a good mind. The main thing is to use it well."
• "Divide each difficulty into as many parts as is feasible and necessary to resolve it" 
• "Doubt is the origin of wisdom." 
• "... Intuition is the undoubting conception of an unclouding and attentive mind, and springs from the light of reason alone."