The tutor comments on subtleties of logic.

According to Harbrace¹, a true statement is one based on widely-accepted, well-supported belief. A valid argument, on the other hand, is based on sound logic. “True” and “valid”, therefore, don’t necessarily apply simultaneously.

The assertion that the infinite series 1+1/2+1/4+1/8+1/16+1/32+….=2 is valid; it can be proven using mathematical logic. Perhaps, however, for it to be true, most people would have to believe it, and be ready to explain why.

That gravity pulls objects to the ground is true, but perhaps difficult to explain or prove with logic.

Perhaps many things we trust are either valid or true, but not necessarily both.

¹Hodges, Horner, et al. Harbrace Handbook for Canadians. Scarborough: Nelson Education, 2003.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.