As they often have done since the Frenchman's appointment as manager, 20th-placed Villa began encouragingly before struggling after conceding the opening goal - on this occasion scored from close range by Jonny Howson.
Diermerci Mbokani headed Norwich's second in the 87th minute after a period in which Villa had enough possession to score but failed to do so.
Despite relegation now appearing a near-inevitability, Garde said: "The quality of the players is there for me.
"The confidence is a key point to playing good football, and you can see, especially, some situations that some of my players are not playing with confidence. You make a technical mistake, you are not free to run everywhere.
"You can say, 'Yes, they are not good enough', but I don't think my players aren't good enough to win games.
"We didn't create enough opportunities to put Norwich under pressure. We had ball possession quite a lot but we were not dangerous in the final third.
"I'm realistic, but in the meantime we have to carry on. The spirit and what we showed in the last two games was not as bad as the results were.
"I will be the last one believing that (survival is) possible. At the moment, after defeat, everybody is disappointed.
"I am realistic as well. I'm not a dreamer, but I am someone who won't run away from his responsibilities. I won't tell you that I am sure we are going to be safe, but take all what I said, don't just take one part of my sentences. I am realistic as well.
"I know that week after week the situation is getting more difficult, but until we can still be safe mathematically, I will believe it."