Full Idea
Hart argues that the smallest heap consists of four objects: three on the bottom, one on the top.
Gist of Idea
The smallest heap has four objects: three on the bottom, one on the top
Source
report of William D. Hart (Hat-Tricks and Heaps [1992]) by Roy Sorensen - Vagueness and Contradiction Intro
Book Reference
Sorensen,Roy: 'Vagueness and Contradiction' [OUP 2004], p.2
A Reaction
If the objects were rough bolders, you could get away with two on the bottom. He's wrong. No one would accept as a 'heap' four minute grains barely visible to the naked eye. No one would describe such a group of items in a supermarket as a heap.