Transition-sentences bring out the logical relation between ideas. You want your paper to read like a continuous argument which good transitions help to facilitate. Words like ‘however’, ‘so’, ‘additionally’ do indicate a logical relation between paragraphs, but they are weak. A strong transition makes the relation explicit.
No transition: In some cultures sympathy plays a role in moral decision-making.
Weaker transition: However, conflicts between principle and emotion more often occur when there is a conflict between the moral values of different cultures.
Stronger transition: While conflict between morality and sympathy can occur in the context of a single cultural code, it more often arises in cross-cultural conflicts.
You also want to avoid using pronouns like ‘this’ to refer to an entire idea, as it’s not always clear what idea you intend to refer to. It is always good to make things explicit.
Weaker transition: Even if this is wrong, relativism does not necessarily promote human well-being and justice.
Stronger transition: Even if a society is able to collectively define its culture and establish its own moral code, relativism does not necessarily promote human well-being and justice.
And who are you asking me to act as ifVirgil is using the sea as a metaphor to show the dual-nature of the Roman Empire. The "face of calm" that Palinurus mistrusts is the empire's appearance of civility and lawfulness. The "monster" that Palinurus guards against is the ugly nature of empirical rule and the brutal means by which it is established. Virgil is telling the Roman people that they must exercise caution in trusting the empire just as Palinurus knows he must exercise caution in trusting the sea because both entities can be pernicious. The sea may have "still waves" but they only hide the rage beneath the surface. Likewise, the empire may be a wonderful idea but, undeniably, it is driven by a violent force.
I did not know the face of this calm sea
and its still waves? Do you ask me to trust
The violent characteristics
of the empire are made painfully clear with the tragic death of Palinurus,
who, in all ways, is the epitome of a good Roman man. In composing
Aeneid Virgil gave Palinurus the role of the pilot to further affirm
his role as a guide, not jsut as the steersman of a ship, but as a guide
in all aspects of life. Palinurus' admirable qualities make him a
respected and valued advisor to Aeneas. Throughout this narrative,
Palinurus trust in ihs instincts and his knowledge from past experiences.
Palinurus has faith in his sophic wisdom: "no even if high Jupiter himself
should guarantee his promise, could I hope to reach the coast of Italy
beneath a sky like this" (Aeneid, V, 11.22-25). Even though
Palinurus is able to acknowledge Aeneas' destiny, he cannot surrender all
of his judgmetn to the prophecies of the gods.
The sentence in purple is an example of how to illustrate the signifiance of a passage. When citing from the text, you want to show what the passage illustrates and how it provides evidence for the claim you are making.
The sentence in blue is an example of a good transition sentence that brings out the logical relationship between these two paragraphs:
 The violent characteristics of the empire are made painfully clear with the tragic death of Palinurus,who, in all ways, is the epitome of a good Roman man.
Here is a good illustration of what I mean by transitions bringing out the relation between paragraphs, thereby making the paper "flow" more smoothly.
 summarizes the point of the previous paragraph
(i.e. that the empire is held together by violence).
 summarizes the point of the current paragraph.
The sentence as a whole connects the two points.