He who knows nothing loves nothing. He who can do nothing understands nothing. He who understands nothing is worthless. But he who understands also loves, notices, sees. The more knowledge is inherent in a thing, the greater the love.

Nature is a light, and by looking at Nature in her own light we will understand her. Visible Nature may be seen in her visible light; invisible Nature may become visible if we acquire the power to perceive her invisible light.

Be not another, if you can be yourself.

Dreams are not without meaning wherever they may come from — from fantasy, from the elements, or from another inspiration.

The art of medicine cannot be inherited, nor can it be copied from books

And it is true, best is nothing concealed which shall not be discovered; for which cause a marvellous being shall come after me, who as yet lives not, and who shall reveal many things.

The dose makes the poison.