Meditations, Book IV, Section 1

Meditations, Book IV, Section 1:

That inward mistress part of man if it be in its own true natural temper, is towards all worldly chances and events ever so disposed and affected, that it will easily turn and apply itself to that which may be, and is within its own power to compass, when that cannot be which at first it intended. For it never doth absolutely addict and apply itself to any one object, but whatsoever it is that it doth now intend and prosecute, it doth prosecute it with exception and reservation; so that whatsoever it is that falls out contrary to its first intentions, even that afterwards it makes its proper object. Even as the fire when it prevails upon those things that are in his way; by which things indeed a little fire would have been quenched, but a great fire doth soon turn to its own nature, and so consume whatsoever comes in his way: yea by those very things it is made greater and greater.

An alternative translation (in the public domain, so reproducible here):

That which rules within, when it is according to nature, is so affected with respect to the events which happen, that it always easily adapts itself to that which is and is presented to it. For it requires no definite material, but it moves towards its purpose, under certain conditions however; and it makes a material for itself out of that which opposes it, as fire lays hold of what falls into it, by which a small light would have been extinguished: but when the fire is strong, it soon appropriates to itself the matter which is heaped on it, and consumes it, and rises higher by means of this very material.

I understand this to mean that it is desirable to adapt oneself to the circumstances and make use of things that are both aligned with and opposed to your purpose.