sign. Reid looks to the way a child learns language, by imitating sounds, becoming aware of them long before it understands the meaning accorded to the various groups of sounds in the artificial state of contemporary adult speech. If, says Reid, the child needed to understand immediately the conceptual content of the words it hears, it would never learn to speak at all. Here Reid distinguishes between natural and artificial signs: "It is by natural signs chiefly that we give force and energy to language; and the less language has of them, it is the less expressive and persuasive. ... Artificial signs signify, but they do not express; they speak to the intellect, as algebraic characters may do, but the passions and the affections and the will hear them not: these continue dormant and inactive, till we speak to them in the language of nature, to which they are all attention and obedience." (p. 52) His external exploration, regarding the senses, led Reid to his critical distinction between 'sensation' and 'perception'. While we become aware of an object through the senses, the content of that perception is not identical with the sum total of the sensations caused in our consciousness. Thus, while we tend to focus on the object perceived, we pay no attention to the process leading from sensation to perception, which contains the knowledge of the thing as real. How, then, do we receive the conviction of the latter's existence? Reid's answer is, by entering into an immediate intuitive relationship with it, as a child does. In the case of the adult, the focus is on perceiving, but with the child, it is on receiving of the sensations in their living nature. For Reid, the perception of the child is different from the adult, and he states that man must become like a child to get past the artificial perception of the adult, which leads to Hume's view that what we perceive is an illusion. Also, the artist provides a key to the true content of sense experience, as he engages the 'language of nature': "It were easy to show, that the fine arts of the musician, the painter, the actor, and the orator, so far as they are expressive .. are nothing else but the language of nature, which we brought into the world with us, but have unlearned by disuse and so find the greatest difficulty