Firstly, the component must have the logic names defined within it. If they aren't defined, then clearly they can't be shown in the schematic.
If they are defined but not displayed, try checking the display settings.
There are three places where the visibility of names is enabled.  These are ANDed, so all three must be enabled for visibility.   
  Level 1. Go to [View], [Display] or click on the 'rainbow' icon.  On the 'Settings and Highlights' tab ensure that 'Pin Names' are set to be visible.
Another minor check is to ensure that the colour used for Pin Names is not the same as the background colour otherwise they will be invisible!
  Level 2.  For any individual components in the Schematic, you can also make the logic names visible/invisible by selecting the component properties from the right click menu. Select the 'Component' tab then adjust the 'Pin Name' check box.
  Level 3.  This is similar to level 2, but in this case only an individual component pad is selected.  Again, the properties must be viewed, but this time select the 'Pad' tab to see the 'Pin Name' check box just for that pad.

An identical capability exists for controlling the display of pin numbers.