If they didn't know it already, Durban businessman Schabir Shaik, Deputy President Jacob Zuma and the South African public are about to discover that law moves like a heavy-duty truck.

It's slow to get going, it's not very manoeuvrable, and it seems to take eons to hit its stride. But once it finally heaves itself into action, it's almost impossible to stop. It crashes through obstacles in the same way that the law can crash through reputations, remorselessly exposing long-held secrets and treating such niceties as political affiliations and personal weakness with equal indifference. Once moved, the law can be simply relentless.

The trial against Shaik concerns events that took place almost five years ago, in what now seems like a different country. Nelson Mandela was president, the trauma of the transition still fresh in the mind. But the trial brings not the past to mind, but the future. It has become almost a truism to say that the trial is not so much about the Shaik's guilt or innocence, although clearly that matters. It is about the behemoth that is never present but always there, Deputy President Jacob Zuma.

Zuma has protested his innocence from the start, and the benefit of doubt must go to him. True, his name is on a document which specifies a payment, essentially a retainer, which the state alleges was asked for and given. True, it is a matter of record that subsequent to this document coming into existence, Zuma intervened in the arms deal investigation, writing a letter to the parliamentary sub-committee against an extended inquiry.

But until the court has spoken, these and dozens of other allegations remain just that. There could be any number of explanations for what Shaik and Zuma are alleged to have done; their actions might have been contrived, or could have been entirely innocent. The picture is only half developed, and we have yet to hear their side of the story.

Zuma's problem is precisely that he is not present but ever present.

The trial holds the prospect that the word of his involvement and his personal life will be spread far and wide. And yet he will not be able to challenge the allegations head-on at the moment they are made. Zuma's lawyers will be present, but there is really no solution for this unfortunate turn of events.

The wheels of justice turn according to their own volition and not always according to the particulars each case might require.

If Shaik were to be found not guilty, the significance of the case would of course immediately dissipate. Shaik would be free to continue with his many business ventures, and Zuma would be free to continue in his bid for the presidency, assuming that is his ambition.

But what if Shaik were found guilty? What would this mean for Zuma's future as a politician and possible president? It might seem that a guilty verdict would be fatal for Zuma's political future. But this, too, depends on the way the trial unfolds. It seems likely on the evidence so far, but it not absolutely outside the realm of possibility that Shaik could have been acting on behalf of Zuma without his knowledge.

If Shaik were to be found guilty, would the state be obliged to charge Zuma? This is an equally tough question, that likewise requires us to suspend judgement. In many countries, Zuma would have been required to stand down already, simply as a matter of honour. It has been his choice not to do so, as it has been the choice of the president to reappoint him to his post. This may be an affirmation of belief in the notion that you are innocent until proven guilty. It may be an affirmation of actual innocence.

In either case, it is not yet time for us to judge. It is time simply to observe the heavy-duty truck that is justice build up its awesome head of steam and to follow in its tracks.

The next few months will require the application of the difficult art of suspending judgement.

With acknowledgement to the Business Day.