Georg Cantor

Mathematics German 1845 – 1918 390 quotes

Created set theory and theory of transfinite numbers

Quotes by Georg Cantor

Two sets are said to have the same power if they can be placed into a one-to-one correspondence with each other.

Ein Beitrag zur Mannigfaltigkeitslehre 1878

The continuum hypothesis is a very plausible proposition, whose proof, however, has so far not been found, despite intense effort.

Letter 1884

The Absolute Infinite is the conception of the maximum, the perfect being, which many call God.

Letter 1886

The finite is annulled in the infinite and becomes zero, but the infinite in the finite is not annulled and does not become zero.

Attributed

The transfinite numbers are not less determinate than the finite numbers, but they are of a higher order of determinateness.

Attributed

The set of all algebraic numbers is countable.

Über eine Eigenschaft des Inbegriffes aller reellen algebraischen Zahlen 1874

The power of the set of points on a line is greater than the power of the set of natural numbers.

Über eine Eigenschaft des Inbegriffes aller reellen algebraischen Zahlen 1874

The introduction of new numbers is justified by the fact that they serve to express relations between magnitudes that could not be expressed by the old numbers.

Mitteilungen zur Lehre vom Transfiniten 1887

The infinite is not a quantity that can be increased or decreased; it is an absolute maximum.

Attributed

The essence of the mathematical mind is not logic but imagination.

Attributed

The set of all subsets of a set has a greater power than the set itself.

Über eine elementare Frage der Mannigfaltigkeitslehre 1891

The transfinite numbers are the numbers of the infinite.

Attributed

The concept of order type is as important for the theory of order as the concept of cardinal number is for the theory of size.

Beiträge zur Begründung der transfiniten Mengenlehre 1895

The truth of my theory will, in time, establish itself, for it is true.

Attributed

The transfinite numbers are in a certain sense themselves new irrationalities and in fact in my opinion the best method of defining the finite irrational numbers is wholly dissimilar to, and I might even say in principle the same as, my method described above of introducing transfinite numbers. One can say unconditionally: the transfinite numbers stand or fall with the finite irrational numbers; they are alike in their most intrinsic nature; for the former like the latter are definite delimited forms or modifications of the actual infinite.

Mitteilungen zur Lehre vom Transfiniten 1887

Had I been influenced by the sterile and hollow admiration of the multitude of mathematicians, or had I believed that my theory should be judged by its utility, I would have long since kept silent.

Letter 1884

Mathematics is entirely free in its development, and its concepts are only linked by the necessity of being consistent, and are in no way constrained by the external world of phenomena.

Grundlagen 1883

The transfinite with its richness of forms and formations necessarily points towards an Absolute, towards the 'true infinite', whose magnitude is not subject to any increase or decrease and which is therefore to be regarded quantitatively as an absolute maximum.

Mitteilungen zur Lehre vom Transfiniten 1886

The potential infinite is nothing but an auxiliary, relational concept, which only points to an unlimited coming-into-being, but never to a fixed, self-contained infinite quantity.

Mitteilungen zur Lehre vom Transfiniten 1886

The finite has been the sole object of mathematics since ancient times. I was the first to investigate the infinite in a systematic way, and to recognize it in its various forms and magnitudes.

Letter 1884