You may have heard the quote attributed to Thomas Edison where he says that genius (or success) is 10% inspiration and 90% perspiration. I am going to prove to you that while the sentiment of the quote may be attributable to Edison, the 10/90 distribution is better attributed to Tesla.

According to a 1932 Harper’s monthly magazine article, the actual percentages that Edison used were 1% inspiration and 99% perspiration although it seems he also sometimes said 2% inspiration and 98% perspiration. For arguments sake, let’s assume he used the first ratio (1:99).

It is well known that Edison and Tesla had their differences. It seems that Edison recognized Tesla’s inventive genius and found occassion to expoit it occassionally. At the same time, Tesla recognized that Edison was a diligent and dedicated inventor but did not always think about problems before trying solutions. Nikola’s opinion on this matter is captured nicely in this quote from Tesla:

“If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of the search. I was a sorry witness to such doings. Knowing a little theory and calculation would have saved him 90% of his labor.”

Tesla noticed that if Edison would use his brain a bit more, or perhaps was a little more inspired he could have saved a lot of his perspiration. Using Tesla’s quote we can quantify the savings a little better.

• Let’s assume that one of Edison’s design tasks takes 100 units of time.
• According to Edison, 1 of those units will be inspiration based and 99 will be perspiration based.
• According to Tesla, if Edison had just thought about things a little bit, he would have been able to save 90% of those 99 units
• In other words, perspiration would have only taken about 9.9 units of time (0.1 \times 99)
• Combine this with the 1 unit of inspiration and add another 1/2 unit of inspiration for a bit more thinking time and the project that formerly would have taken 100 units of time, now will take
9.9 + 1.5 = 11.4 units of time
• This means that success/genius is
• \frac{1.5}{11.4} = 13 \% inspiration and
• \frac{9.9}{11.4} = 87 \% perspiration
• With a bit of rounding we could say that success is 10% inspiration and 90% inspiration arriving back at the original quote I mentioned which is not what Edison actually stated. It only becomes true after applying Tesla’s modification,
• Proving once again that Tesla > Edison