On the other hand, there are a few strengths to this statement. One strength is that it is supported by the plausible scientific data that, we need to use observation and experiment to find out about the world around us. Empiricists believe that since we are born with our minds being a ‘tabula rasa’ we need sense experience to acquire all substantive knowledge about the world. Also it explains how we acquire some knowledge that is not gained through sense experience, but rather is a priori, simply by saying that all such knowledge is actually about the meaning of words. However there are still objections put forward by rationalist philosophers, to criticise these statements.
One of the main objections of the statement that ‘all knowledge comes from sense experience’ is that empiricism leads to scepticism. Rationalist philosopher Descartes argues that sense experience is too unreliable to give us genuine knowledge of the world. He believes that the only way to gain real knowledge of the world is through reason. Descartes argues this in his three waves of doubt. Each wave is stronger than the last. The first wave is that, his senses have deceived him in the past, so it is sensible to never trust entirely something that has deceived you already. So he can’t trust his senses. However, since our senses have ensured human survival for thousands of years, it’s fairly trustworthy. The second wave of doubt states that he has often dreamed he was sitting by the fire in his dressing gown. For all he knows, he could be dreaming, so he can’t trust his senses, even when they tell him things about his immediate surroundings. Descartes counters this himself and says even if he is dreaming now; his dreams would have to be constructed from experiences in real life outside of the dream. The third wave of doubt is that an evil demon could be deceiving us, and that all our sense experiences are actually false. So he can’t trust his sense as it could be potentially be caused by an evil demon. He replies to this by saying ‘cogito ergo sum’. If he can think about his existence, then he must exist, the demon can’t deceive him of his existence. Although the three waves of doubt knock down the reliability of experience, and that we cannot be completely certain of the things we believe on the basis of experience. It doesn’t disprove that on the basis of experience, many things might still be probably true.
Another objection to the statement that ‘all knowledge comes from sense experience’ is that we can gain knowledge of the world through reason. Opposing the empiricist’s view that substantive truths about the world can only be known through sense experience, rationalists like Descartes argue that we can know such truths through reason alone. For example, you can prove that God exists through a priori arguments like the trademark argument. The trademark argument states that nothing can be caused by something less perfect than itself. So if my idea of God were caused by something other than God, I wouldn’t have the idea of perfection. In this argument, the idea of perfection is something we don’t experience to understand. Therefore, having knowledge of an all perfect being can’t have come from sense experience. However there are problems with the trademark argument, for example the butterfly effect: if a butterfly flaps its wings, it could cause a hurricane in the other side of the world. A lesser cause, having a greater effect. Therefore with this major problem, the trademark argument poses little threat the empiricists view.
Furthermore, another objection is that there are in fact some synthetic a priori truths, for example the truths of mathematics e.g. 2+2=4. This is clearly a priori, but it doesn’t seem to be analytic because we know it is true, however it is not simply true just by definition. Also the basic truths of morality, for example, knowing that needless suffering is bad. This also seems to be a priori, but once again, not analytic because we don’t need to experience someone telling us that is bad, for us to already think that. In addition there are philosophical truths, for example the ontological argument doesn’t work. This again seems to be a priori, however not analytic, as it’s not true just by definition. Therefore this leads to the idea that empiricism itself may be self defeating, since it seems like it is neither analytic nor based on sense-experience.
by
mightybean (student)
