CHAPTER ONE
1.0     Introduction
Are we not often at times shocked by the discovery that what we thought was certain is later proved dubious and false? If this be a regular occurrence, is it not the case that we may become suspicious of all claims to certainty? But then, the history of human opinion rightly forms the most fertile source material for the development of any theory of knowledge. Yet, no theory or belief has proved so full of absurdity, that it lacked its own disciples. The history of science is itself replete with theories priory accepted by the sages of old but later on discredited.
Philosophers are therefore concerned with the basis of all knowledge claims, so that they might arrive at a consensus for judging these claims. For it, much of what had been taken as certain has instead been proved false or sceptical. Then, what can we really know and how can we really ever be certain?
Such were the feelings of David Hume, as he posited his philosophy of “impression and ideas” of which this work is to throw more light on.  
The philosophy of David Hume then is both an attack on rationalism and a “reducto and absurdum” of empiricism since the empiricism he defines is one-sided as the rationalism he attacks. He frankly confessed his dissatisfaction with his position in a passage which seems to be the starting point for a consideration of the outline of his work.:
There are two principles which I cannot render consistent nor is it in my power to renounce either of them, namely, that all our distinct perceptions are distinct existence, and that the mind never perceives any real connection among distinct existence.[1]
Thus, the appeal to those two principles and the understanding of them is the key of Hume’s work. The first principle, that what we can distinguish in perception is distinguished in existence is subjective. I rather see it as making the articulations and distinctions of things depend on the distinctions of the mind. But the second principle is based on the opposite assumptions.
Hume’s whole account of causation depends on his perception that causation is not a relation among the mind’s own ideas, in the sense that it can be got at by any kind of introspection or reflection. Thus, the result of Hume’s theory of causation seems to be subjective when he reduces the conception of necessary connection to a feeling, and this is precisely because he believes that causation is a relation between real existences and cannot be perceived by the mind. About causation, he said:
Causation is a relation, which can be traced beyond our senses and informs us of existence and objects, which we do not see or feel.[2]
In Hume’s philosophy, the theory of the “association of ideas” plays  the most important part and was the most recognized in the later  history of English Empiricism. No wonder Hume was constantly making association the work of the understanding and through this theory, he succeeded in narrowing the fundamental principles of knowledge to mere feeling. His account of the general principle; also lobbied his explanation of particular instances of cause and effect. Thus, little did he mean to think that by causation, we only mean constant conjunction, but that we sometimes infer causation from the observation of only one instance.
In his own period, Hume affected the inheritance of the Cartesian rationalism into empiricism and made atomization of perception the very nerve of his philosophy. From this insight, he viewed every question especially metaphysical and proposed every solution.
It is then our task in this work, to expose the implications of the concept of his “impressions – ideas” theory, which evidently forms his basic epistemological stand. We shall therefore see how plausible they are with a critical mind.