It is logically possible that the world sprang into being 5 minutes ago as it is now, with the population “remembering” a wholly unreal past.
Descartes publishes his text called the meditations. The meditations is his attempt at logically deducing what we, as humans, can know for certain. How does he do this? In his first meditation, he takes a skeptical approach and says that knowledge derived from the senses is untrustworthy because the senses can be deceived. For example, our judgment of distances can be inaccurate as objects can seem larger or smaller than they are. The things we know about science, astronomy and medicine can also be doubted. Surely, he asks, I cannot doubt that I am in my room sitting by the fire clothed in a winter dressing gown. However, I have had dreams of sitting by the fire that seemed so real! Even if I can tell that I am dreaming or not, it’s still possible that a malevolent demon is deceiving my senses and the world before me is merely an illusion. Is there anything left that I can call certain? Even if I am being deceived, the notion that I can doubt anything means that I am, at the very least, thinking and to think must mean I exist. The one thing I know for certain is I EXIST.
Even if Descartes premises are shaky i.e. doubting I can be dreaming, doesn't the conclusion still ring true?
The idea of God is us thinking of a 4d object, we can conceive of the idea but it is beyond our scope because of the nature of God as a perfect and infinite being
This method of doubt tries to reveal if there is anything we know that cannot be doubted, that we can know of with complete certainty.
Descartes asks us to indulge in this skeptical thought to reveal what we can know for certain.
Descartes wasn't a skeptic, uses skeptical doubt as a tool of discovery. To temporarily cast aside assured beliefs if they can be doubted
Moving forward, to know about the existence of God, other minds and bodies we have to prove it from our own consciousness. It has to be an a priori truth
Thomas Nagel believes that we can never know what it is like to be a bat. The bat’s experiences are exclusive to itself - the subjective character experience: “An organism has conscious mental states if and only if there is something that it is like to be that organism – something that it is like for the organism.”. From this, only our own mental activity is the only thing that is unquestionable.
The term passions can be understood as emotions, feelings and/or desires. Hume believes that our passions are the prevailing force in how we go about our lives and places our ability to reason as merely trying to make sense of things
This falls in line with Hume’s belief that reason is not the faculty that allows us to achieve knowledge and aligns with the empiricist notion that knowledge is derived from experiences and sense perceptions (although Hume ultimately believes that we can’t know anything for certain)
In context, the prevailing idea was reason, going as far back as the Stoics, Aristotle, Plato etc. and Hume’s assertion that reason ultimately takes a back seat, unsettling traditional thought at the time.
Hume's explanation is that Humans are essentially animals and are mechanistic in our way of living. Just like any other animal, one of our main objectives is to survive and continue functioning; reasoning isn’t the driving motivation but the faculty to which we make sense of things. The Rationalists, on the other hand, assert the world can be understood when we make logical connections - a way in which we truly come to understand things.
Passions are the ultimate motivation, the goodness and badness of things motivate you regardless of reason e.g. reason tells me I need to study or do chores but I have no desire to do these. However, studying can lead to greater feelings and hence, the bigger motivator.
The stoics take on the same ideas as the Cynics (defying social convention and living in accordance with nature), the 2 main rules the stoics follow: detachment from external circumstances and living in harmony with nature. Though defying convention was part of the Stoic fabric, it was adhered to in a more conservative fashion than their Cynic counterparts.
They sought the highest good which is virtue apatheia - A way of living that isn’t burdened by emotions. Achieving apatheia is having rational control of the emotions. The Stoics saw the passions as confused ideas that required reasoning to formulate them into distinct and clear ideas
How does this translate in practice? Reason gives you the ability to handle circumstances beyond your control, you gain a rational detachment to achieve the best possible situation for yourself. Cicero gives the following example, albeit, an extreme one: A virtuous man even while being tortured on the rack, his body mutilated and searing with pain, and isolated from all his family and friends, is maximally happy.
In terms of epistemology, The Stoics also take an empiricist approach and say that all that exists is particulars - there are no immaterial forces, anything we can learn from is material. Just like Hume, the Stoics deny innate ideas and contend that the mind is “tabula rasa”: a blank slate.