Both Uses of

inferior
in
Zen and the Art of Motorcycle Maintenance

From these hypotheses he deduces a series of theorems among which it's impossible to find any contradiction, and he constructs a geometry whose faultless logic is inferior in nothing to that of the Euclidian geometry.†
Part 3

inferior = (adjective) of low quality, or of lower quality or rank than something else OR (more rarely as a noun) a person of lower rank or status

Good tools, as a rule, don't wear out, and good secondhand tools are much better than inferior new ones.†
Part 3 *

Definitions:

(1) (inferior)
of low quality, or of lower quality or rank than something else -- sometimes used as a noun to refer to a person of lower rank or status
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Less commonly, specialized senses include:
- anatomy and botany -- a lower position on a body or plant (or pointed downward)
- typography -- a character that drops beneath a printing line (such as with subscript)
- astronomy -- having an orbit relative to the sun that is lower than earth's (making Mercury and Venus inferior planets)