Analysis and Differential Equations

[A]t the close of the Middle Ages, when the so-called Arabic figures became established throughout Europe with the symbol 0 and the principle of local value, immediate progress was made in the art of reckoning. The problems... led up to the general solutions of equations of the third and fourth degree by the Italian mathematicians of the sixteenth century. Yet even these discoveries were made in somewhat the same manner as problems in mental arithmetic are now solved in common schools; for the present signs of plus, minus, and equality, the radical and exponential signs, and especially the systematic use of letters for denoting general quantities in algebra, had not yet become universal. The last step was definitively due to... Vieta... and the mighty advancement of analysis resulting therefrom can hardly be measured or imagined.

The word Analysis signifies the general and particular heads of a discourse, with their mutual connections, both co-ordinate and subordinate, drawn out into one or more tables.

Fortunately analysis is not the only way to resolve inner conflicts. Life itself still remains a very effective therapist... The therapy effected by life itself is not, however, within one's control. Neither hardships nor friendships nor religious experience can be arranged to meet the needs of the particular individual. Life as a therapist is ruthless; circumstances that are helpful to one neurotic may entirely crush another.