Written January 2, 2013

     “Excuse me, sir, I’m asking.”

     “Yes, Sendagire, go on.”

     It was our ten minute session at the end of a chemistry class at Ntare School in Mbarara, Uganda in 1961, a time set aside for students to ask questions on any part of the lesson they didn’t understand.

     “It’s about positive and negative, sir."

     “Yes, go on. What is it about positive and negative?”

     “It is confusing, sir. You have taught us that in an electric circuit electrons flow from the negative to the positive. Isn’t that right, sir?”

     “Yes, that is correct.”

     “But, sir, if negative flows to the positive, it must be moving, acting, sir. We have been led to believe if something is moving and active it is positive. And now in chemistry, if it is acting, doing, why isn’t it called positive?”

     “Oh, I see, and you are absolutely right. A long time ago, researchers discovered that there were two opposite types of electric charges, and they could have been called just as you say one black the other white, but they were designated positive and negative, and, had those scientists been as analytical as you are now, they would have been named as you suggest, but they agreed to call them as we are calling them now and it would be too confusing to change them now.

      “You said agreed. Is that the way much knowledge is based on agreements made long ago?”

     “What do you mean?”

     “I am thinking about electrons: We can’t see them, sir, but they agreed long ago that electrons exist.”

     “But there is evidence that they exist. We can test that evidence.”

     “But, sir, I am thinking about math also, sir. There are rules about which we have no proof, but they are accepted. We use them consistently to solve problems, sir.

     “Such as what?”

     “I think one word is axiom, a self evident truth. I can’t think of the other.”

     But here another boy, Mugisha, stepped in to help.  “We talked about postulates, which I think are like axioms... and theorem, which is an idea or belief, or method generally accepted as true, but it needs a proof.”

     They all chorused in. “We cannot. How can we, as students, accept that, sir?”

     A spirited discussion followed. “Proof,where was the proof?”

This conversation occurred in a high school chemistry class in which the now-serving president of Uganda was then a student. I am sure I learned as much in that class as did the students, and yet I have in front of me a book written by the president entitled Sowing the Mustard Seed, in which he has inscribed the following:

30/12/2009

To: Mzee Moses Howard

Of the USA (formerly of Ntare 1961-62)

From: President Museveni of Uganda

“You were a great chemistry teacher.

You solved the problem of valence

for me.”

President Museveni’s book, Sowing the Mustard Seed, is a history of Uganda during and soon after the coup of Idi Amin. It covers years following the coup. It describes the country during the revolution in which the president and his fellow students fought a bush war, deposed Amin and are now serving as rulers of their country.