Besides which it will make me the better listened to; for "He that is ignorant (says the proverb) receives not the words of knowledge, unless thou first tell him that which is in his own heart." We will therefore make a coasting voyage along the shores of the arts and sciences received; not without importing into them some useful things by the way.
In laying out the divisions of the sciences however, I take into account not only things already invented and known, but likewise things omitted which ought to be there.

For there are found in the intellectual as in the terrestial globe waste regions as well as cultivated ones.

It is no wonder therefore if I am sometimes obliged to depart from the ordinary divisions.

For in adding to the total you necessarily alter the parts and sections; and the received divisions of the sciences are fitted only to the received sum of them as it stands now.
With regard to those things which I shall mark down as omitted, I intend not merely to set down a simple title or a concise argument of that which is wanted.

For as often as I have occasion to report anything as deficient, the nature of which is at all obscure, so that men may not perhaps easily understand what I mean or what the work is which I have in my head, I shall always (provided it be a matter of any worth) take care to subjoin either directions for the execution of such work, or else a portion of the work itself executed by myself as a sample of the whole: thus giving assistance in every case either by work or by counsel.