In this lecture, Vivekananda relays the orthodox understanding of the Puranas:
... although we have the Vedas for our scriptures, we have Smritis and Purânas — subsequent writings — to illustrate the doctrines of the Vedas; these of course have not the same weight as the Vedas. And the law is that wherever these Puranas and Smritis differ from any part of the Shruti, the Shruti must be followed and the Smriti rejected.
Here he says,
To understand Bhakti, therefore, we have got to understand these Puranas of ours.
He praises Puranas once again:
We have not only to acknowledge the power of the Puranas in our own day, but we ought to be grateful to them as they gave us in the past a more comprehensive and a better popular religion than what the degraded later-day Buddhism was leading us to.
But later on he takes a very negative stance against the Smritis, Puranas, and even orthodox followers like Shankaracharya and Ramanujacharya:
The Smritis and the Puranas are productions of men of limited intelligence and are full of fallacies, errors, the feelings of class and malice. Only parts of them breathing broadness of spirit and love are acceptable, the rest are to be rejected. The Upanishads and the Gita are the true scriptures; Rama, Krishna, Buddha, Chaitanya, Nanak, Kabir, and so on are the true Avatâras, for they had their hearts broad as the sky — and above all, Ramakrishna. Ramanuja, Shankara etc., seem to have been mere Pundits with much narrowness of heart. Where is that love, that weeping heart at the sorrow of others? — Dry pedantry of the Pundit — and the feeling of only oneself getting to salvation hurry-scurry! But is that going to be possible, sir? Was it ever likely or will it ever be so? Can anything be attained with any shred of "I" left anyhow?
This statement is unorthodox and he is even calling the Rishis like Vyasa "men of limited intelligence":
The Smritis and the Puranas are productions of men of limited intelligence and are full of fallacies, errors, the feelings of class and malice.
This statement is also unorthodox because he is now going by his own personal feelings of what should be accepted or rejected:
Only parts of them breathing broadness of spirit and love are acceptable, the rest are to be rejected.
and contradicts his own previous assertion:
The Puranas and other religious scriptures are all denoted by the word "Smriti". And their authority goes so far as they follow the Vedas and do not contradict them.
This is another unorthodox statement:
The Upanishads and the Gita are the true scriptures;
What is his basis for that?
Then he also takes a jab at great Vedantic scholars:
Ramanuja, Shankara etc., seem to have been mere Pundits with much narrowness of heart.
Did Vivekananda's opinions on Hinduism change over time?