Step 1: Write the given equation.
\[
\sin \theta = \csc \theta = \dfrac{1}{\sin \theta}
\]
Step 2: Multiply both sides by $\sin \theta$.
\[
\sin^2 \theta = 1
\]
\[
\sin \theta = 1
\]
Step 3: Find $\theta$.
For $\sin \theta = 1$, within $0 \leq \theta \leq \dfrac{\pi}{2}$, we have $\theta = \dfrac{\pi}{2}$.