This is also reminiscent of Descartes’ cogito:
X cannot occur without Y. X occurs. Therefore, Y exists.
(X=thought; Y=a thinking thing)
Except that’s actually valid logic.
For all X, X implies Y; X, therefore Y.
As opposed to For all X, Y is required of X; Y or not Y, therefore X. <-- invalid logic is invalid.
For all X, Y is required of X; Y or not Y, therefore X.
This is also reminiscent of Descartes’ cogito:
X cannot occur without Y. X occurs. Therefore, Y exists.
(X=thought; Y=a thinking thing)
Except that’s actually valid logic.
For all X, X implies Y; X, therefore Y.
As opposed to
For all X, Y is required of X; Y or not Y, therefore X.
<-- invalid logic is invalid.