What is Shifting ground fallacy?

People may employ hedging to make their contentions ambiguous, or they may use a definitional retreat to claim that their words meant something else. In the third version of this defensive type of operation, they may actually change the whole ground they were maintaining, while still claiming continuity. When people do shift the substance of what they were saying, they commit the fallacy of shifting ground.

I said I liked the project and thought it a good one. However, I share the objections you have all voiced, and can only say how much this rein-forces a view I have long held that it is not enough for a project to be likeable and good.
(A leap from one bank to the other with the grace of a ballet dancer superimposed on the desperation of a stranded man.)

The deception is the source of the fallacy. Criticism of the original stance is avoided by shifting to a different one. In that the argument has taken place about the position as understood, it is irrelevant to the new position which is now claimed. Similarly a critique now has to start all over again on the new position because what has passed so far has not been centered upon it.

I said we'd come out stronger after this election. Look, we both know that many things can strengthen a party. I have always thought it source of strength if a party can respond to criticism. Now, with our share of the poll down to 9 per cent, I think that…' 
(This can be seen in every election by every party except the winner. It is roughly equivalent to 'I don't think that a score of five goals to one against us should be seen as a defeat for Scottish football. It is more of a challenge which…')

The shifting sands of political fortune often coincide with the shifting ground of the fallacy. This is because of a patently absurd rule that no politician must ever change his mind about any-thing. To do so would be to admit he was wrong before, and could, by implication, be wrong now. Infallibility must, there-fore, be sustained. Shifting ground, insecure though it might look to us, provides a solid foundation for political continuity.

There is a certain class of religious argument in which any-thing at all whose existence is assented to can be called divine. Here the base of discussion seems to slide quite happily across several continents, as what started out as a discussion about a man in the sky with a white beard ends up in consideration of some abstract principle of the universe.

Shifting ground is for defensive use. You cannot convince others of a new point with it, but you can use it to avoid it being known that you were wrong. As the victorious armies march into your territory after the struggle, they are surprised to find you at the head of them, leading the invasion. They had quite mistakenly supposed that you were head of the defense forces.

After hearing his point of view, I feel that Mr Smith’s amendment to insert the word ‘not’ into my motion expresses the spirit of what I was trying to say. I therefore accept his amendment as an improvement to my motion.

There are muscular exercises which you should practise every day in front of a mirror, and which assist the mental contortions needed to shift ground rapidly.

Yes, I walked through the green line, customs officer, and I can explain that extra bottle of scotch.
(Does anyone spot the slight tremor in his feet?)