It’s tempting to quote from some great authority to give credence to what you’re saying. But in TOK, it’s your analysis of ideas that matters, so add your own critique of the quotation to show that you’ve understood it and thought about it. An “undigested” quote will not necessarily “prove” the point you are trying to make and on its own, it is not enough. For example:
Knowledge issue: Considering history and human Science, how do we know if we are free?
Quotation:“Men think themselves free because they are conscious of their actions, but ignorant of their causes.” (Spinoza)
Personal comment:This quotation illuminates the idea of freedom being an illusion. In science, Heisenberg’s uncertainty principle observes that we cannot know the position and velocity of subatomic particles and so from this persepctive, events are goverened by pure chance. The implication of this is that there is no obvious link between cause and effect. Spinoza said that if falling stones were conscious they might well believe they were falling of their own free will. Based on this argment our notion of free will is no more that something we imagine. However, a counter-argument is that physicists also agree that the law of cause and effect still operates when observing anything bigger than sub-atomic particles. We may be ignorant of the precise causes of all our actions but this does not imply that we have no free will. The strongest evidence for this is our real sense that when faced with a choice we can genuinely choose which one we want.
Here the philosopher Daniel Dennett is interviewed about free will: http://philosophybites.com/2012/08/daniel-dennett-on-free-will-worth-wanting.html