- by Đạt Vũ
- 29/12/22
Loading
You guys may be used to hear about “necessary and sufficient condition” in Maths. But this is just a shortcut, the full one must include 3 types: necessary condition, sufficient condition and necessary and sufficient condition. These concepts also play a very important role in philosophy reasoning, so understanding them will facilitate you in analyzing important arguments in philosophy.
Now, think about “mammals” and “cat”. The concept “mammals” has a wider meaning than the concept “cat” because: to be a mammal, an animal can have a lot of options such as cat, dog, goat, buffalo, cow, pig, horse, whale… while to be a cat, an animal only has a sole option, that is cat.
Therefore, we say:
In general, we say:
A is a necessary condition of B if whenever we get B, we get A but not whenever we get A, we get B
A is a sufficient condition of B if whenever we get A, we get B but not whenever we get B, we get A
But, wait, what about the necessary and sufficient condition. It turns out to be very easy. That happens when both directions are true: A is a necessary and sufficient condition of B if whenever we get A, we get B and whenever we get B, we get A.
If we say mind is a necessary condition of body, it means with any body, we have a mind but with any mind, we do not always have a body.
If we say mind is sufficient condition of body, it means with any mind, we have a body but with any body, we do not always have a mind.
If we say, mind is necessary and sufficient condition of body, it means whenever we have a mind, we have a body and whenever we have a body, we have a mind.
Please take note, because we will use these to analyzing Cogito the famous argument of Descartes
These concepts are easy to understand but also easy to be confused. Let’s practice with a small quiz: