In conformity to the nature of the universe every single thing is accomplished, for certainly it is not in conformity to any other nature that each thing is accomplished, either a nature which externally comprehends this, or a nature which is comprehended within this nature, or a nature external and independent of this.
If a thing is difficult to be accomplished by thyself, do not think that it is impossible for man: but if anything is possible for man and conformable to his nature, think that this can be attained by thyself too.
Practise thyself even in the things which thou despairest of accomplishing. For even the left hand, which is ineffectual for all other things for want of practice, holds the bridle more vigorously than the right hand; for it has been practised in this.