Athens — Early next year, when the Greek Parliament is expected to pass a new election system, President Constantine Caramanlis will decide whether to seek a second term.
Both events are seen as being as important to Greece as the restoration of democracy was a decade ago.
Mr. Caramanlis is widely viewed as a guarantor of stability in Greece. In many ways, a Greek president reigns while the prime minister rules. Mr. Caramanlis has struck a patriarchal pose above party politics, serving as a symbol of national unity and conciliation.
Unlike Socialist Prime Minister Andreas Papandreou, Caramanlis is a conservative. He served as prime minister from 1955 to 1963, and again from the fall of the dictatorship in 1973 until 1980.
Parliament elects the president. Nevertheless the president has substantial powers, including vetoing certain legislation or dissolving Parliament. Only the president can call elections or referendums.
To the dismay of many on the right and the satisfaction of the left, Caramanlis has not used those powers. He has seldom intervened publicly, and then only to scold all political parties when he considers the political debate too harsh and divisive.
2 ''Papandreou is the elected head of government,'' said a source close to him. ''As such he is responsible for government policy. The President respects that. But there is a tacit understanding, a recognition, that certain issues are of national significance, above politics. Both know what they are and so there is an equilibrium.''
For example, it is the consensus here that Caramanlis would intervene to prevent a move to withdraw Greece from the European Community or the North Atlantic Treaty Organization. But as the last three years have shown, he would not try to block or dictate government policy while Greece remains within those bodies.
Polls support the general view that many centrist Greeks helped vote the Socialists into power in 1981 despite a mistrust of Mr. Papandreou, believing Cara-manlis provided a safety net as president.
Within Caramanlis's former party, New Democracy, there is some bitterness over his role. A New Democracy member of Parliament said: ''Everybody knows Cara-manlis gave (Papandreou) the margin of victory. And now he will do it again.''
An observer with close ties to Papan-dreou adds, ''They are more popular as a team than individually.''
The next president will be elected by Parliament in April. Parliamentary elections must be held by October 1985.
Papandreou would clearly like to see Caramanlis remain as president. He has often praised his role and characterized their personal relationship as ''excellent.'' The prime minister has publicly indicated he would support the candidacy of his erstwhile political rival.
Caramanlis refuses to reveal his plans,thus maintaining influence on the January debate in Parliament on a new electoral system.
Papandreou pledged in 1981 to replace the current system with a pure proportional system. He has modified that stance somewhat, asserting that the new system should not exclude any political force but should ensure ''stable government.''
Political sources here say Caramanlis wants to prevent the sort of gerrymandering - a tradition he himself deftly used in the past - that would allow a party with less than 45 percent of the vote (in normal times an excellent result in Greece) to win a large majority of seats.
According to the same sources, Caramanlis gambled when he became president in 1980 that neither New Democracy nor Pasok (Papan-dreou's Socialist party) would win a sufficient majority in the October 1981 elections to form a one-party government. He expected a close election to cast him as coalition builder.
They say Caramanlis believes political factions are canceled out in such a system, thus producing moderate, predictable, and, despite sometimes chaotic appearances, stable government. Papandreou's landslide in 1981 dashed any hopes the President might act as kingmaker.
''He has his chance again,'' said a conservative politician. ''He doesn't intend to miss.''
6 Recent speculation has centered on a proposal whereby 200 of the 300 seats in Parliament would be filled through pure proportional representation, thus ensuring no political force is excluded from Parliament.
The other 100 seats would be divided between the two largest parties on a predetermined ratio.
Finally, some claim Caramanlis is holding out for a pledge from Papan-dreou that he will not seek to form a government with communist support. Such an event would create a deep political crisis. It could even bring Caramanlis himself back into the political fray.