What is the author's tone in Black Pioneers of Science and Invention by Louis Haber?

The tone used in BLACK PIONEERS OF SCIENCE AND INVENTION by Louis Haber is for the most part, objective. The purpose of the work is to introduce the inventions and contributions of fourteen men dating from the 18th to 20th centuries.

It would have been easy to create a subjective view of the doctors and inventors in the book, particularly in light of the obstacles each had to overcome in order to live out his dream. At no time is the tone of the work combative, regardless of the injustices often faced by the Pioneers.