I see no contradiction.
But then, I have been doing the Buddhist practices for over 13 years, under the guidance of my local teacher who is one of the Dalai Lama's monks.
Buddhism cannot be understood intellectually.
How can you explain to someone who has never sneezed what a sneeze feels like? No words convey it.
How can you explain to a dream what it is like to be awake? No words convey it.
In Buddhism it is only doing the practices, those of learning to be observe with clarity, that you start to see what the words of the teachings actually are trying to convey. You have to see it for yourself. It takes anywhere between 3 and 8 years of daily practice before you start to get the first glimmers of understanding.
For all those who try to understand Buddhism with mental logic and intellectual reasoning ... good luck. You are only getting caught up in the ego of your intellect, and cannot arrive at any actual comprehension through that route. There ARE things in life that words cannot convey, despite the Western worship of intellect.
The Heart Sutra says that BOTH dualism and non-dualism are true. You have to actually start to BE in that head space to grasp what it is saying.
There can be no path (no attainment), when you already are there. It's a matter of taking off your blindfold, and this theoretically can be done immediately .. but it pretty much works out to having to easy that blindfold off very slowly. People work so hard to GET somewhere, and the Heart Sutra reminds us that we already ARE there .. the problem is in our misperception of reality.