The French philosopher Pascal once wrote: "The eternal silence of these infinite spaces terrifies me." The quotation came to mind while listening to a long-time observer of the peace process discussing the text of the Belfast Agreement and its implications.

"There are a number of silences in there," he said. Most importantly, in the current context, the Agreement did not spell out precisely when the shadow executive had to be established.

The Agreement may not be explicit on the subject but it will be a poor politician or civil servant who cannot find some implicit reference to justify his or her stance on this crucial topic.

A senior unionist argued that the Agreement did not require the establishment of an executive until the formal transfer of powers from Westminster in early spring. By implication there was no need for a shadow executive, and the northern Cabinet need not meet until the day the Assembly was formally and officially inaugurated in all its pomp and ceremony.

But others would argue that close analysis of the text shows that the Agreement gives certain pointers on this key matter. Thus, under the heading "Transitional Arrangements", there is a reference to the transitional period between last June's Assembly elections and the formal transfer of powers next year, when "those members of the Assembly serving as shadow Ministers shall affirm their commitment to non-violence".

Clearly, then, the Agreement envisaged the appointment of shadow Ministers. There is another significant reference in the section headed "Executive Authority" which states: "Following the election of the First Minister and Deputy First Minister, the posts of Ministers will be allocated to parties . . ."

The text does not spell out how quickly after the election of the First and Deputy First Ministers the other portfolios will be allocated. Some - mainly nationalists and republicans - will argue that it should be as soon as possible; others, particularly the UUP - will maintain there is no hurry.

Here we enter that grey area between high and low politics. The SDLP and, possibly even more, Sinn Fein, need the shadow cabinet to be up and running quickly. But the quicker it is set up, the more difficult life will be for the unionist leadership.

The one thing that could make life easier for the unionists would be some form of IRA decommissioning - Mr Trimble has even hinted that the Provisionals could do the job themselves under verifiable conditions.

Put ideas like that to republicans and they react as if you had asked them to don an Orange sash and march down the Garvaghy Road behind a "Kick the Pope" band.

Nor are they in any way receptive, at least at this stage, to the notion that, say, the hand over or destruction of Semtex could be accompanied by a significant scaling-down of the British army presence plus the closure of that extraordinary network of mountain-top security installations in South Armagh.

This is where the meeting scheduled for tomorrow between Mr Trimble and the Sinn Fein president, Mr Gerry Adams, comes in. Nobody has been given any reason to expect that there will be movement on decommissioning during that encounter but there is a quiet hope that it will, in that time-honoured phrase from peace process-speak, "Move the process forward".

It is a delicate child, this peace process. But rather than contemplating the dangers inherent in its present condition, insiders urge us to look at the contrast between now and this time last year.

Then, there was a wrangle over working out rules of procedure so that Sinn Fein could at least be in the same room as the unionists, even if Mr Trimble and his friends were still addressing everything through the chair. In retrospect it seems almost comical, like a particularly demented episode of Fawlty Towers, but at the time it was deadly serious.

NOW, the peace boomers say, we have an Adams statement indicating a desire to see an end to the conflict; Mr Martin McGuinness is representing Sinn Fein on the decommissioning body; the "Real IRA" has announced a complete cessation of violence; there has been a round-table meeting on Monday involving the UUP and Sinn Fein during which Mr Trimble and Mr Adams exchanged views with admittedly frigid courtesy; and we are on the threshold of a historic face-to-face encounter, with Seamus Mallon available as referee if required.

"Never say ONLY a symbol," we are told, and there is a heavy symbolic burden attaching to the encounter. The content of what passes between the two leaders tomorrow may be less important than their demeanour afterwards.

The aftermath of Monday's meeting was encouraging in that respect: both Mr Trimble and Mr Adams did a good job of containing what must have been fairly turbulent internal emotions.

The old saying that "Today's freedom-fighter is tomorrow's statesman" could be applied to Mr Adams. In the case of Mr Trimble, perhaps we should say: "Today's hardliner is tomorrow's diplomat."