Controversy Quote by Leonhard Euler
“Notable enough, however, are the controversies over the series 1 - 1 + 1 - 1 + 1 - ... whose sum was given by Leibniz as 1/2, although others disagree. ... Understanding of this question is to be sought in the word "sum"; this idea, if thus conceived - namely, the sum of a series is said to be that quantity to which it is brought closer as more terms of the series are taken - has relevance only for convergent series, and we should in general give up the idea of sum for divergent series.”
About This Quote
Source Treatise: Introductory to Analysis, 1748
Leibniz’s series sum 1/2 applies only to convergent series; divergent series lack a true sum.
In simple terms: Only convergent series have a definite sum.
Treat divergent series differently.
Themes
Mood
Type
When to use this quote
- calculus teaching
- advanced mathematics research
- theoretical physics
- numerical methods
Key Concepts
Questions to Reflect On
- How do we handle divergent series in practice?
- What alternative summation techniques exist?
Divergent series can be assigned summation methods, but they differ from ordinary sums.