The next level is Doctrine. Doctrine is the development of truth on the basis of deposit and dogma. It can develop and even contradict itself over time. It is largely the thoughts of people. It has not been declared offically true or false by the church.
This particular point, quoted above, contradicts the teaching of the Magisterium.
A doctrine is a teaching of the Magisterium. The Magisterium teaches either infallibly or non-infallibly. The infallible teachings are called dogmas; a dogma is a doctrine that has been taught infallibly by the Magisterium. Any doctrine taught by the Magisterium but not taught infallibly by the Magisterium, is a non-infallible teaching.
These teachings (doctrines) are not merely the thoughts of people. And they are in fact official teachings of the Church. There is a possibility of error and reform in non-infallible teachings, but it is a limited possibility. And the faithful are required to give the religious submission of will and intellect to these non-infallible teachings.
Can. 750 §1. A person must believe with divine and Catholic faith all those things contained in the word of God, written or handed on, that is, in the one deposit of faith entrusted to the Church, and at the same time proposed as divinely revealed either by **the solemn magisterium of the Church or by its ordinary and universal magisterium **which is manifested by the common adherence of the Christian faithful under the leadership of the sacred magisterium; therefore all are bound to avoid any doctrines whatsoever contrary to them.
[the above quote discusses the infallible teachings of the Magisterium]
§2. Each and every thing which is proposed definitively by the magisterium of the Church concerning the doctrine of faith and morals, that is, each and every thing which is required to safeguard reverently and to expound faithfully the same deposit of faith, is also to be firm-ly embraced and retained; therefore, one who rejects those propositions which are to be held definitively is opposed to the doctrine of the Catholic Church.
[this next section, above, refers to the non-infallible teachings]
Can. 752 Although not an assent of faith, a religious submission of the intellect and will must be given to a doctrine which the Supreme Pontiff or the college of bishops declares concerning faith or morals when they exercise the authentic magisterium, even if they do not intend to proclaim it by definitive act; therefore, the Christian faithful are to take care to avoid those things which do not agree with it.
[we are not free to disregard non-infallible teachings, nor can we consider these teachings to be merely ‘the thoughts of people’]
I recommend Germaine Grisez’s book, Fulfillment in Christ, which has a particularly good, succinct explanation of the Magisterium.