Letters

⁶ “Whence then comes our capacity of conceiving in thought things which we have never seen?” What, think you, can be the cause of this, but a certain faculty of diminution and addition which is innate in the mind, and which it cannot but carry with it wherever it turns (a faculty which may be observed especially in relation to numbers)? By the exercise of this faculty, if the image of a crow, for example, which is very familiar to the eye, be set before the eye of the mind, as it were, it may be brought, by the taking away of some features and the addition of others, to almost any image such as never was seen by the eye. By this faculty also it comes to pass, that when men's minds habitually ponder such things, figures of this kind force their way as it were unbidden into their thoughts. Therefore it is possible for the mind, by taking away, as has been said, some things from objects which the senses have brought within its knowledge, and by adding some things, to produce in the exercise of imagination that which, as a whole, was never within the observation of any of the senses; but the parts of it had all been within such observation, though found in a variety of different things: e.g., when we were boys, born and brought up in an inland district, we could already form some idea of the sea, after we had seen water even in a small cup; but the flavour of strawberries and of cherries could in no wise enter our conceptions before we tasted these fruits in Italy. Hence it is also, that those who have been born blind know not what to answer when they are asked about light and colours. For those who have never perceived coloured objects by the senses are not capable of having the images of such objects in the mind.

7. And let it not appear to you strange, that though the mind is present in and intermingled with all those images which in the nature of things are figured or can be pictured by us, these are not evolved by the mind from within itself before it has received them through the senses from without. For we also find that, along with anger, joy, and other such emotions, we produce changes in our bodily aspect and complexion, before our thinking faculty even conceives that we have the power of producing such images [or indications of our feeling]. These follow upon the experience of the emotion in those wonderful ways (especially deserving your attentive consideration), which consist in the repeated action and reaction of hidden numbers in the soul, without the intervention of any image of illusive material things. Whence I would have you understand— perceiving as you do that so many movements of the mind go on wholly independently of the images in question— that of all the movements of the mind by which it may conceivably attain to the knowledge of bodies, every other is more likely than the process of creating forms of sensible things by unaided thought, because I do not think that it is capable of any such conceptions before it uses the body and the senses.

Wherefore, my well beloved and most amiable brother, by the friendship which unites us, and by our faith in the divine law itself, I would warn you never to link yourself in friendship with those shadows of the realm of darkness, and to break off without delay whatever friendship may have been begun between you and them. That resistance to the sway of the bodily senses which it is our most sacred duty to practise, is wholly abandoned if we treat with fondness and flattery the blows and wounds which the senses inflict upon us.