Calculus (n) *Latin ~ *Small stone used for counting.

Usage:

1. (Mathematics) a branch of mathematics, developed independently by Newton and Leibniz. Both differential calculus and integral calculus are concerned with the effect on a function of an infinitesimal change in the independent variable as it tends to zero.

2. (Mathematics) any mathematical system of calculation involving the use of symbols

3. (Philosophy / Logic) Logic an uninterpreted formal system

4. (Medicine / Pathology) pl -li [-ˌlaɪ] Pathol a stonelike concretion of minerals and salts found in ducts or hollow organs of the body

So which definition does Blair mean when he uses his new phrase ‘Calculus of risk’?

*1. (Mathematics) a branch of mathematics, developed independently by Newton and Leibniz. Both differential calculus and integral calculus are concerned with the effect on a function of an infinitesimal change in the independent variable as it tends to zero.
2. (Mathematics) any mathematical system of calculation involving the use of symbols*

Calculus is a branch of mathematics concerned with change. You can look into differential calculus and discover rate of change. For example given a speed-time graph you can find the acceleration using the method of differentiation – the gradient of the speed curve = acceleration. Alternatively, looking at integral calculus, the same speed-time graph can be used to find the total distance traveled, which is the area under the graph. A good way to look at it is changing between dimensions: differentiation – down a dimension and integration – up a dimension.

Both methods can be explained by studying increasingly smaller changes in the variable x (time in the speed-time graph) so that, conceptually, the difference between one input ‘x’ and the next is infinitesimally small.

Trying to put this into context of Blair’s usage and attempting to turn it into an equation, I can only speculate that he means quantifiable risk measuring the output ‘reward’ plotted on the axis of evil.

To differentiate the ‘equation’ might result in a rate of change, but I am more interested in what he though the integral effects of any war waged would be. The sum of all risk-reward options as the change in risk tends towards zero.

Now, I’m not privy to Blair’s idiosyncratic equation measuring reward against risk, I suppose that’s part of the Chilcot Inquiry – to discover whether his equation makes sense, is well defined and it reporting sensible answers. But it seems, to my humble self, that Blair has manipulated the change in risk by attempting to ensure that people were behind *him, *rather than behind his *strategy* or *logic. *One of his repetitive justifications is that he was doing what *he thought* was the right thing, perhaps in the hope that that the ‘change in risk’ of public opinion turning sour tends towards zero for each increment along the scale of actions and their relative extremities. Using this assumption for his approximation he has appeared to have used methods of calculus to enter into a higher dimension (which is a discovery of mathematics I’m sure he favours, given his new phrase). But are his methods of seeking support sound? Well we’ve heard rumours of fabrication, ignoring advice and sexing up anything they could get their hands on. Of course it’s not for me to opine politically, but if we’re talking maths here, then its no matter for debate that the incorrect input can result in the incorrect output.

Of course he could mean the philosophical definition:

*3. (Philosophy / Logic) Logic an uninterpreted formal system *

Closely related to the 2nd mathematical definition above, the logical calculus in which the expressions include predicate letters and variables, as well as the expressions for truth-functions and the propositional variables of the propositional calculus.* Hmmm… truth function. I’m sure he likes the sound of that, too.*

So, for example, IF Saddam Hussain has wmd THEN he must be removed.

Or, perhaps: IF Saddam has wmd THEN we have an excuse for regime change.

Of course, it doesn’t tell you what to do if your predicate turns out to be incorrect – you have the relationship between predicate and subject wrong? For most it’s back to the drawing board, but for some perhaps they enlist the help of the aforementioned ‘higher dimensions’..

But by his own admission, this calculus of risk changed after the terrorist attacks on the World Trade Center in 2001, an emotive and terrifying event, but what did his predicate change from? And what to? Will we ever find out?

Of course there is the medical definition:

*4. (Medicine / Pathology) pl -li [-ˌlaɪ] Pathol a stonelike concretion of minerals and salts found in ducts or hollow organs of the body *

While I do think this definition has more to do with the original Latin meaning of the word, it certainly gives me a stone in the pit of my stomach.