The moment one constructs a device to carry into practice a crude idea, he finds himself unavoidably engrossed with the details of the apparatus. As he goes on improving and reconstructing, his force of concentration diminishes and he loses sight of the great underlying principle. Results may be obtained, but always at the sacrifice of quality. My method is different. I do not rush into actual work. When I get an idea, I start at once building it up in my imagination. I change the construction, make improvements and operate the device in my mind. It is absolutely immaterial to me whether I run my turbine in thought or test it in my shop. I even note if it is out of balance. There is no difference whatever; the results are the same. In this way I am able to rapidly develop and perfect a conception without touching anything. When I have gone so far as to embody in the invention every possible improvement I can think of and see no fauly anywhere, I put into concrete form this final product of my brain. Invariably my device works as I conceived that it should, and the experiment comes out exactly as I planned it. In twenty years there has not been a single exception. Why should it be otherwise? Engineering, electrical and mechanical, is positive in results. There is scarcely a subject that cannot be examined beforehand, from the available theoretical and practical data. The carrying out into practice of a crude idea as is being done, is, I hold, nothing but a waste of energy, money, and time.

The pressure of occupation and the incessant stream of impressions pouring into our consciousness through all the gateways of knowledge make modern existence hazardous in many ways. Most persons are so absorbed in the contemplation of the outside world that they are wholly oblivious to what is passing on within themselves. The premature death of millions is primarily traceable to this cause. Even among those who exercise care, it is a common mistake to avoid the imaginary, and ignore the real dangers. And what is true of an individual also applies, more or less, to a people as a whole.

I seem to have acted under the first instinctive impulse which later dominated me -- to harness the energies of nature to the service of man.

A new idea must not be judged by its immediate results. Many technical men, very able in their special departments, but dominated by a pedantic spirit and nearsighted...

- from My Inventions, The Autobiography of Nikola Tesla