Why "oxygen" and "intelligence" confuse people

In "Straight and Crooked Thinking", Robert Thouless explains that ordinary non-technical people find words such as "oxygen" and "intelligence" confusing because the same word is used with different meanings by experts and by laypeople, or for several different things.

Oxygen

• To a chemist, oxygen is a specific chemical element, a gas with fixed properties.
• To an ordinary person, oxygen may mean "the part of the air which is good for us" or "something in an oxygen cylinder or in medicine", and the layman may not know that it is a single chemical element found in many compounds such as water.
• When a word is used in several senses, people argue or draw conclusions without realising that the meaning has shifted.

Intelligence

• To a psychologist, intelligence may be a quality measured by tests (such as IQ).
• To an ordinary person it can mean cleverness, quickness, good sense, general ability, or even information, as in "intelligence service".
• People therefore disagree about "intelligence" while actually talking about different things.

Why this causes confusion

1. A single word has several meanings (ambiguity).
2. Technical words enter everyday speech and change meaning.
3. Words fail to separate clearly the different varieties of the "same" thing.

Thus the confusion is in the words, not in the facts. Clear definition of terms is the remedy.